I may not have been drawing, but whilst on the plane and train I had a LOT of time to write down things! I wrote the continuation of Alex In Wonderland with the King where Alex licks his feet and armpits before eating him out in his bedroom and sinking into his bed. I also wrote a bit of the next Costume Shop bonus comic where Finn and Osiris get to body worship Umbra, who eventually transforms and vores them for fun.
The major thing was that I sketched out some character designs for the next story for Funhouse Of Frights called CLOWN HOUSE. I tried a few designs including my character David, and a vaguely red headed wizard I find hot, but I ended up going for the other four. I also wrote the entirety of that comic panel by panel, which I will start working on this or next month, with the background and environments being a simple bouncy house so I can make it much faster.
This also gives you a bit of an insight into how I write or put ideas together, I usually panel them out based on how I write them.