My standard raise in .25/.5 was to 1.75. Decreasing to this and then following up with around the same on the flop should be sufficient to take it if someone has nothing (and doesn't think you bluff all the time). If you get called and nothing develops the turn is a check/fold unless I have a solid read telling me otherwise. Yes, it gives away the bluff (and you might want to skip following up a missed flop with a bet the next couple of times), but it's better than pouring more money into a losing hand when your opponent has already shown that they will call you.

- Jeffrey