Do you bet when you have a good flush draw and are first to act? If so how much?

I bet draws frequently, and I usually bet just under what I could justify calling if I was bet into with a second caller (three total in the pot). For example, flush draw with $20 in the pot. I'm a little worse than 4:1 to make the hand, so I'm willing to bet out for $8. If I get two callers, that adds up to 36:8, and I get my odds.

I think the advantages to betting it are that:

1) Often everyone missed and you can pick up the pot (obvious)
2) You show strength and keep the button from a big buy attempt if it checks around (pretty obvious)
3) You put more money in the pot so you get odds to see the next card, and to add value if you hit (obvious, but the first part is debatable).
4) You set up for a play later when you have a very strong hand and want an all-in from the oamf across the table.(new to me)

The only solid disadvantages I considered before is that you are putting money in a pot when you don't have the best hand, when you MIGHT have gotten to see a card for free. Plus, someone with a very strong hand can re-raise, and all of a sudden things get serious.

I'm now seeing that there is another big disadvantage. It is so obvious that you are betting a draw when you don't bet to take away the draw odds. I've noticed that a lot of players are reading this and I'm automatically into the re-raise scenario. I've also started picking up on this, and going over the top to take away the odds for their draw.

Of course this doesn't work on the brainless. You gotta know who you're playing for this to work.

Thoughts?