Say if have a really nice 2-bar riff that I like a lot. How would I go about composing a song around that?
Ok, the obvious answer is "play it a few times, then make some variation of it, play that a few times, then play the original a few more times, or play a new variation, and repeat a few times over..." But what I'm looking for is some well recognised and specific methodologies for doing this. Are there any?
If you understand modes you can get a good indication as to what note or chord progressions can work.
A simpler method is to look at a chord wheel, which will give you directions which you can move.
http://photo.goodreads.com/books/1180676064l/1064839.jpg
I tend to use a bit of both of those, but my key method is just to jam with others and just play riffs around each other. Your riff might fit a particular chord sequence, and then your jamming partner may head off a different direction which may work or not- either way it will give you ideas.
