When I shoot, I don't rely on one shot for each situation. Say someone is standing by the window and the light is catching them just right. I won't just snap one or two; I'll run off a string of them, each a little different. I did this when I shot film, too. Something as simple as a blink can kill a shot, and with SLRs, that's hard to watch for. If it's a really good situation, I may run off a dozen or more. There are many times when I can't do this, and I've gotten great shots when it's been the only one to choose from, but if given the option, I'll take the insurance. To some people this will sound like a shotgun approach, but for me, it's about choices once I get them into the "darkroom". I shoot shallow DOF, so being just slightly off can mess up an image. It sometimes takes quite a few shots to get all of the variables to line up just right. You can end up with some happy surprises or different takes on a theme, too.