I finished my Clarinet Sonata this weekend! After inundating myself with Benny Goodman songs, I got into the right mindset, started noodling around on my clarinet, and came up with a tune that I was happy with. From there, it was no problem to develop it into a nice 2.5-minute rondo. It's a little like the first movement, with a faster tempo and a more pronounced walking bass line, but I think it compliments the other two movements and matches them, stylistically.
Unlike the first two movements, I wrote a few of the riffs without the clarinet in hand, so I'll have to take a little time learning to play what I've written and maybe altering it a little to better fit under my hands. It should be a lot of fun getting this one together, though.