Here's a real quick tutorial for how to make smoke plumes like these. They are extremely easy to make and are very inexpensive and they make the battlefield look better (and work well for showing when you've popped smoke launchers, too). For materials, you need only some polyester pillow stuffing (fiberfill), some paint, and though it's not required, some spare flying bases.
Take some fiberfill and make your smoke shape, almost anything will do, but making it wider at the base will help keep it upright. Once you get a good shape, you're ready to paint! Dark red on the bottom, some orange a little higher, and yellow as a final highlight. Bleed over a little into the areas you don't want it so each new color overlaps, that means after these three you'll have more yellow than the final coloring - this will keep the white of the fiberfill from showing through in the final product. I went with light gray next, though either way would probably work, and then black at the end. I went with this to blend with the white fiberfill, making a little lightness visible on the inside, but going full black and then highlighting with lighter would look good as well. Use some of your smoke colors over the fire portion to make it look like smoke is coming from the side of the blaze. For an alternative (like for smoke launchers instead of just wrecks), you can just leave off the fire portion of the coloring.
As a final step, coat a flying base in PVA glue, then put a little on the bottom of the plume and stick it in. This helps weight the bottom to keep it upright and gives it a little more structure, but the paint will actually do a good job stiffening up the fiberfill and keeping it from sticking to everything as much. A final matte polyurethane coat keeps everything uniform and together, and you're done!