I just recently finished reading the book "Two Sides of the Moon", written by David Scott (from Apollo 9 and 15) and Alexei Leonov (the Soviet Union's star cosmonaut after Yuri Gagarin died: he did the world's first EVA on Voskhod 2, trained for Soyuz 10 to dock with Salyut 1, trained for the Soviet moon landing, and flew on the first Apollo-Soyuz joint mission).
One thing that particularly caught my interest, with regards to learning for CLLARE, was a story by Scott about a small problem on Apollo 15: more than once they had a problem with water leaking from cooling systems and forming large "puddles" in both the CM and LM. Each time they managed to stop the leak and then clean up with towels, so these weren't major problems. But what really struck me was: it would never have occurred to me to bring a towel into space, but the guys on Apollo clearly had several.
It's obviously important to spend a significant amount of time and effort thinking of things it might be useful to bring onboard. This is a fairly simple, non-technical task which anybody in our community should be able to help with. I think it would be worth while to start a Wiki page for brainstorming ideas, and post it to /r/tothemoon and encourage everybody to chip in. This list can get as long as it likes, when the time comes to actually make a final list we can rank the suggested items by importance and just truncate it after the total mass exceeds some limit. Do people think this is a good idea?
On a related note: we don't really have a good formal process in place for handling things like this. The Engineering Process is great for making technical decisions that involve making a choice amongst several options, but for this kind of problem (and others like menu planning) the Design Task Tree is really no good. It would be nice if we could come up with a general system for handling this kind of planning.