It never seems to be enough free stuff to go around. The issue actually is the small amount of time to search for good resources – because there is plenty of free, good quality stuff out there that designers or future illustrators offer to those interested in creating. For that reasons, I gathered a few useful brushes that give a really nice effect to your final graphic. They are all free but don’t forget to give credit to their makers.
Free Photoshop Smoke Brushes