Magick spells are cast by burning herbs (incense), thus releasing their magick power into the atmosphere (fumigation).
One of the most ancient methods of casting spells is consciously, carefully and deliberately burning herbs. This method incorporates all four primal elements into one spell. By applying the power of fire, herbal power (which has been nourished by Earth and by water), is transformed into smoke (air) and dispersed into the atmosphere to provide magickal solutions and fulfill magickal desires. If you burn incense on a metal pan or burner, then you incorporate what many consider to be the fifth element, metal, into your spell as well.
Modern incense frequently taken the form of sticks and cones, which require a little technical know=how. However, incense is an ancient, ancient art. If cave people had the technology to create fine, viable incense, of course you do, too. The material original incense was loose dried herbal material, ground and powdered. Most magick spells assume incense will be in this form.
Mortars and pestles are ancient magickal, medical and culinary tools. They may be used to break down and blend herbal material. Once upon a time, incense was created by repeated grinding with a mortar and pestle, and then sifting with a sieve (also an ancient magick tool). However, if you desire the fine powder that many spells specify, a coffee or spice grinder, particularly an old-fashioned manual one, can make life easier.
If you prefer stick incense, blanks may be purchased and doctored to your taste.