equity question

I understand that a flush draw will hit 35% of the time by the river, so if I'm against 3 opponents and only contributing 25% of the pot, I have an equity edge at that point. But if I'm only against one or two generic opponents (all things being equal), how should my approach change? If I'm responsible for 33% of the pot, do I still bet my "even" pot equity? Plus, if I'm heads up, do I tend to lay back? This is assuming I have no read or desire to get tricky with my opponents. Thanks guys.