Stereo Miking Techniques
So you just got yourself some preamps and a pair of mics. You try to get those drums/guitar/piano etc. tracks laid down but it just does not sound right. It may seem like a simple enough thing to just point the mic and hit record but there are a few things to consider beforehand. The polar phase of the two signals can kill the recording. Audiotuts' 6 Stereo Miking Techniques You Can Use Today post will give you some basic guidelines on how to configure your mic arrangement to tackle your phase problems and get the best stereo depth from your recordings.
If you have already recorded your takes and think you might be having phasing problems try nudging one of the tracks left or right by a few milliseconds. You could also grab the highly recommended and free plugin Flux Stereo Tool to invert the phase of either side of the stereo signal and keep an eye on things.