You can use smoke as a disappearing trick. When spotted, throw down
some smoke. After the smoke fills, move to a different location and hide. The smoke will conceal your movement, and the enemy won't be able to know where you hide and can't determine which direction you headed and most likely won't ever be able to find you.You can also use smoke if you are rushing.Throw a smoke grenade into an open area or passage and run through it ,hiden from enemy snipers.You can easily flank them and take them out causing panic into the whole enemy team.