BriTANick, the guys behind hilarious sketch videos, recently did a Reddit IAmA. In it someone asked about how they come up with sketch ideas. Which is cool, because that's one of those "I shouldn't ask this because I don't want to feel stupid" kind of questions. But those are the questions a lot of people want to know the answers to.
And answer they did. Their advice for writing sketch is very similar to what many people believe to be the key to the creative process: talk until you find something interesting. Seems a little devoid of magic, but it works great.
This ties back to today's other post about creativity. Keep things comfortable and messy. And good stuff comes out.