Betting flush draws into a field OOP

Everyone is talking about betting flush draws on the flop to create a pot and odds. You can also take it down UI sometimes. However, I only see all this working if you also lead the flop with many other hands. If your opponents know you will only lead into a large field with a flush draw, then they will either 1) Kill your action by raising or 2) Call you down and fold when the flush hits. To me, in order to make these bets pay off, you have to be willing to lead with other hands in blind position such as TP, top two, or a straight draw. It seems like many players replying in this post only lead out of blinds with a flush draw.