It depends on whom I’m fighting and what troops are present. One thing I never do is drop them on the first turn. The most common thing I do, however, is drop them on the objective a turn or two before the rest of the army is there. Using them to hold the objective from early game on is usually suicide for them, but mid-game on it’s usually a good idea. Another thing I use them for is for patching up holes in my line where the enemy threatens to flank or break through. The latter is usually what I use them for.
One house rule we use was one posted on here some time ago, where you have to roll a d6 after choosing what hex you’re targetting for a drop. On a 1-4 you’re dead on. On a 5-6 you drop to a hex adjacent to the hex (which is easily determined since the game uses d6s on a game where spaces have 6 sides).
-=Grim=-