I cable tie a cell phone clip to my bike so I can just snap my phone on the bike. Mine is around the headset, I have an older nokia phone. It doesn't seem like much of a tip but I'm surprized at how many people have trouble carrying their phones.
I just used non-clorinated brake cleaner to hose off my cassette and rear deraillure. I don't know if that's a good tip yet or not, maybe somebody will chime in. I only did it once and it did not hurt anything.