Also, appending to this:
If you do have horrid overlapping on your effects, try rearranging the order in which ParticleClasses are called. BZ2 stacks the effects on top of one another, so BZ2 will attempt to render particleClass1 under everything, and particleClass9 on top of everything. This also holds true for draw_multi effects.
When making dust effects, always go with a neutral color so it blends with all maps. I use a very light brown: "212 196 181 15". This makes an offwhite almost completely clear cloud good for unit trails. Note: Pure colors look VERY out of place in dust effects.
Do not overuse matte (solid) colors, they tend to look bland, repetetive, and very cartoony, especially in "one one modulate" (additive) effects.
Alpha Channeled textures (like smoke) do not need a matte white base and an overcomplicated alpha channel to look good. Instead, you can put an image that, when channeled into transparency, will make the particle look a ton more textured, and the end result of this has the potential to look extraordinary! Note though, that the darker the ODF reference of the TGA is, the less detail of this effect there will be, so test first at "255 255 255 255" and scale down from there. An example of this will be in the next SRV release (2.35.PB4a at the time of writing), as the ground scorches left by units.