Q: (and if so, how do you find a good intro) or are you just built different
A: i have no idea how to do it. sometimes it's good to check what happens right before it returns to the first section the second time. sometimes the right intro will be hiding there. on the other hand, sometimes a misdirect is best: use something that makes it sound like you are NOT about to play the song that's about to happen (so that when it does, it's a surprise). I still don't have a reliable technique for finding an intro to a song which seems to have been born without an intro. But maybe the best way is to write a scene for the song to spring from. that method might be the most powerful