I've just been to a camp of sorts, and there was a cellist who could play piano something awesome (including improvised piano jazz accompaniment). He was playing piano in Bb (a swing beat) and I found out that I can do a little improvising. The only real thing to keep in mind of are the chord progressions and the beat and you're pretty well set to play what you want via blues scales, minor key, major key with some alterations, etc. Any advice? To continue learning, I mean.