Trump use. When to pull trumps
To Draw or not to draw?
When planning the play, your first decision has to be: To draw trumps immediately, or not?
If you have no shortage in some suit or another in the short trump hand (often the dummy), then DRAW TRUMPS IMMEDIATELY. This is true even if you are missing AKQ of trumps. Without a shortage you can't ruff. But if you don't draw your opponents' trumps that's exactly what they might do to you. By shortage, I mean void, singleton or doubleton.
It's no good ruffing in the long hand, since these trumps would have won eventually anyway. All you are doing is using your trumps without consuming the enemy's.