Beware that many plants (if not all!) smell quite different when
being smoldered. Sweet scents turn sour fast.

The Two Forms of Incense
Incense is virtually a necessity in magical practice, but there seems to
 be a great mystery surrounding its composition. Fortunately with practice,
 it's surprisingly easy to make incense. Two types of incense are used in magic:
the combustible and the noncombustible. The former contains potassium nitrate
 (saltpeter) to aid in burning, while the latter does not. Therefore combustible
incense can be burned in the form of bricks, cones, sticks and other shapes, whereas
noncombustible incense must be be sprinkled onto glowing charcoal blocks to
release its fragrance. Ninety-five percent of the incense used in magic is the
 noncombustible, raw or granular type. Why? Perhaps because it's easier to
make. Herbal magicians are notoriously practical people. Also, some spells
(particularly divinatory or evocational rites) call for billowing clouds of
smoke. Since cone, sticks and block incense burn at steady rates,
 such effects are impossible with their use. 

Noncombustible Incense
Be sure you have all the necessary ingredients. If you lack any, and decide
 to substitute please see the substitution section on this site for ideas! Each
 ingredient must be finely ground, preferably to a powder, using either a mortar
and pestle or an electric grinder. Some resins won't powder easily, but with practice
 you'll find the right touch. When all is ready, fix your mind on the incense's
goal - protection, love, health. In large wooden or ceramic bowl, mix the resins
and gums together with your hands. While mingling these powder - vibrating
with your magical goal - exiting your hands and effective than its commercial
 counterparts. Next, mix in all the powdered leaves, barks, flowers and roots.
As you mix, continue to visualize or concentrate on the incense goal. Now add
any oils or liquids (wine, honey, etc.) that are included in the recipe. Just a few
 drops are usually sufficient. On the of oils: If there's a sufficient amount of
dry ingredients in the recipe, you can substitute an oil for an herb you lack. Simply
 ensure that the oil is an essential oil, for synthetics smell like burning plastic
when smoldered. Once all has been thoroughly mixed, add any powdered gemstones
or other power boosters. A few - not many - of the recipes on this website will 
call for a pinch of powdered stone. To produce this, simply take a small stone
 of the required type and pound it in a metal mortar and pestle (Or simple smash
 it with a hammer against a hard surface). Grind the resulting pieces into a powder
and add no more than the scantest pinch to the incense. One general power-boosting
"Stone" is amber. A pinch of this fossilized resin added to any mixture will
 increase its effectiveness, but this can be rather expensive. The incense
is now fully compounded. Empower the incense, and it is done. Store in a tightly
capped jar. Label carefully, including the name of the incense and
date of composition. It is ready for use when needed.

Combustible Incense
Combustible Incense (in form of cones, blocks and sticks) is fairly complex in
 its composition, but many feel the results are worth the extra work. To be blunt,
 this aspect of incense composition isn't easy. Some of the ingredients are difficult
 to obtain, the procedure tends to be messy and frustrating, and some even question
whether combustible incense is as magically effective as noncombustible counterpart.
Some hesitated making or using sticks, cones or blocks because they
 contain potassium nitrate. This substance is magically related to Mars, and some
 feel this might add unneeded aggressive energies to the incense. Gum tragacanth
 glue or mucilage is the basic ingredient of all molded incenses. Gum tragacanth is
available at some herb stores; at one time in the past drugstore carried it. It is rather
 expensive ($3,00 an ounce it is at right now, while am typing this) but a little
will last you for months. To make tragacanth glue, place a teaspoon of the ground
 herb in a glass of warm water. Mix thoroughly until all particles are dispersed. 
To facilitate this, place in a bowl and whisk or beat with an egg beater. This will cause
foam to rise, but it can be easily skimmed off or allowed to disperse. The gum
 tragacanth has enormous absorption qualities; an ounce will absorb up to one
 gallon of water in a week. Let the tragacanth absorb the water until it becomes a thick,
bitter-smelling paste. The consistency of the mixture depends on the form of the incense
desired. For sticks (The most difficult kind to make) the mixture should be
relatively thin. For blocks and cones a thicker mucilage should be made. This is where
practice comes in handy after a session or two you will automatically know when 
the mucilage is at the correct consistency. If you can't find tragacanth, try using
 gum Arabic in its place. This, too, absorbs water. I never tried using gum Arabic, but
from what I've heard it works just as well as tragacanth. Next, make up the incense base.
Not all formulas on this site can be for combustible incense; in fact, most
of them were design to be used as noncombustible incenses. (So if you have any
 recipes for combustible incense please send them to me so I can put
 them up!) Fortunately, by adding the incense to a base it should work well.
Here's one standard formula for an incense base:

Cone Incense Base
6 Parts Charcoal (not self-igniting)
1 Part ground Benzoin
2 Parts ground Sandalwood
1 Part ground Orris root (This "fixes" the scent)
6 Drops essential oil (use the oil form of one of the ingredient in the incense)
2 to 4 Parts mixed, empowered incense

Mix the first four ingredients until all are well blended. Add the drops of
essential oil and mix again with your hands. The goal is to create a powdered mixture
with a fine texture. If you wish, run the mixture through a grinder or the mortar
and pestle again until it is satisfactory. Add two to four parts of the completed
and empowered incense mixture (create according to the instructions for Non
 combustible Incense above). Combine this well with your hands. Then
using a small kitchen scale, weigh the completed incense and add ten percent
 potassium nitrate. If you've made ten ounce of incense, add one ounce of
 potassium nitrate. Mix this until the white powder is thoroughly blended.
Saltpeter should constitute no more than ten percent of the completed bulk of the
 incense. If any more is added, it will burn to fast; less, and it might not burn at all.
Potassium nitrate isn't difficult to obtain. I buy mine at drugstores, so check there 
(it isn't usually on the shelf; ask for it at the pharmacy). If you have no luck try
 a chemical supply stores. Next, add the tragacanth glue. Do this a teaspoon at
a time, mixing with your hands in a large bowl until all ingredients are wetted.
For cone incense you'll need a very stiff, dough-like texture. If it is too thick
 it won't properly form into cones and will take forever to dry. The mixture
should mold easily and hold its shape. On a piece pf waxed paper, shape he mixture
into basic cone shapes, exactly like the ones you've probably bought. If this
form isn't used, the incense might not properly burn. When you've made
up your cone incense, let it dry for two to seven days
in a warm place. Your incense is finish!

For Block Incense: Make a 1/3 inch-thick square of the stiff dough
on waxed paper. But with a knife into one-inch cubes as if you
were cutting small brownies. Separately slightly and let dry.
Stick Incense: It can be attempted as well. Add more tragacanth glue to
 the mixed incense and base until the mixture is wet but still rather thick.
 The trick here is in determining the proper appropriate materials to use. 
Professional incense manufacturer use thin bamboo splints, which aren't
 available. So try homemade wooden or bamboo splints, broom straws,
very thin twigs, or those long wooden cocktail skewers that are available
 at some grocery and oriental food stores. Dip the sticks into the
 mixture, let them sit upright and then dip again. Several dipping
are usually necessary; this is a most difficult process. When the sticks
 have accumulated a sufficient amount of the incense, poke them into
a slab of clay or some other substance so the they stand upright. Allow them to dry.

Cone Incense Base #2
6 Parts Sandalwood (Or Cedar, Pine, Juniper)
2 Parts powdered Benzoin (or Frankincense, Myrrh, etc.)
1 Part ground Orris root
6 Drops essential oil (use the oil form of one of the cense ingredients)
3 to 5 Parts empowered incense mixture.

In this recipe, powdered wood is used in place of the charcoal. Use sandalwood
if it's included in the incense recipe. If not, use cedar, pine or juniper, depending on
 the type of incense to be made. Try to match the wood base of this incense to
 the incense's recipe. If you can't, simply use sandalwood. Mix the first three
ingredients until combined. Add the oil and mix again. Then add three to five
parts of the completed incense to this. Again, this should be a powder.
Weigh and add ten percent potassium nitrate. Mix, add the gum 
tragacanth glue, combine again and mold in the methods described above.

Rules Of Combustible Incense Composition
Here are some guidelines to follow when compounding combustible incense.
These are for use with the Cone incense Base #2 recipe above.
 If they aren't followed, he incense won't properly burn. there's less room 
for experimentation here than with noncombustible incenses. First off, never  
use more than ten percent saltpeter, Ever! Also, keep woods (such as
sandalwood, wood aloe, cedar, juniper and pine) and gum resins (Frankincense,
 myrrh, benzoin, copal) in the proper proportions: at least twice as much
 powdered wood as resins. If there's more resinous matter, the mixture won't
burn. Naturally, depending on the type of incense you're adding to the base,
you may have to juggle some proportions accordingly. Simply ensure that
 frankincense and its kin never constitute more than one-third of the
final mixture, and all should be well. Though this small link doesn't
 provide you with all the information, the info here
 should be sufficient enough for you to experiment!  

Simple Incenses
These are one-herb incenses that can be burned on charcoal when needed.
In effect these are instant incenses, they need no mixing or measuring.
Simply grind and empower them before use.

Allspice: Burn to attract money & luck & to provide extra physical energy.
Arabic, Gum: Use for purification & protection of the home.
Bay: Use a small amount for purification, healing, protection & to sharpen psychic powers.
Benzoin: For purification, prosperity & increasing mental powers.
Cedar: Smolder for purification, protection, to speed healing & promote spirituality, & to obtain money.
Cinnamon: Burn to sharpen psychic powers, to draw money, speed healing confer protection & to strengthen love.
Clove: Protection, exorcism, money, love & purification.
Copal: Burn for protection, cleansing, purification, to promote spirituality, & to purify quartz crystals and other stones before use in magic.
Dragon's Blood: Use for love, protection, exorcism & sexual potency.
Fern: Burn the dried fronds indoors to exorcise evil, & outdoors to bring rain.
Frankincense: Protection, exorcism, spirituality, love & consecration.
Juniper: Exorcism, protection, healing & love.
Myrrh: Healing, protection, exorcism, peace, consecration, meditation.
Pine: Smolder for money, purification, healing & exorcism
Rosemary: Burn for protection, exorcism, purification, healing & to cause sleep; to restore or maintain youth, to bring love & to increase intellectual powers.
Sage: Smolder to promote healing & spirituality.
Sandalwood: For protection, healing, exorcism, spirituality.
Thyme: Health, healing, purification.

Information was taken from 'The complete Book of incense, oil & brews' By Scott Cunningham