Replying to Making a good panoramic shot- need some tips

I tried making  a few panoramic shots today. some of them came out pretty well i think, but  a big problem i am having is that sometimes the images dont line up properly when they get stitched together. i am using a program that does it for me though. is a more hands on approach the best way (doing it in photoshop)? how can i make them line up better? what are some good tips? should i take a lot of pics or only a few with overlaps?