Whenever I had a good start previously and it developed on flop, I would slow play. Unfortunately doing so would cost me the game.
People make comments about runner runner,river rat, etc., They get all teed off when someone catches their hand to beat their leading hand. They go "why did you keep calling?" (Well why didnt you/we bet heavier?)
I'm a firm believer of accepting responsibility for one's own fault and not blaming it on the other guy. It's like the syndrome of an "open cookie jar". If you leave it open, someone's going to snatch a few. That's what I did when I checked or bet extremely lightly. I let the guy/gal catch me. I literally said come snatch some cookies out of my open cookie jar.
So I say, if you don't want the river rat or runner to do you in, then don't make it so easy for them to do it. I learned that the hard way. Now when I have a hand I give it the bet it deserves. If someone wants to hit over me, they have to pay dearly. See trying to trick or trap someone else by playing slow, as so many have mentioned earlier, can certainly backfire on you. Your supposedly craftiness can create your own doom and have you locked out of a tourney you may have otherwise aced.