I occasionally take on commissions. Lately I haven't, only because of my nasty work schedule, and two pre-existing commissions I needed to finish up first, but I have done my fair share of commissions in the past. Commissions can be a funny thing though, and can put folks in a right awkward spot depending on how comfortable you are with them, how much you want to charge, how badly you want to get your name out there as a commission painter/sculptor/etc., techniques you will or wont do, where you will and won't ship to, etcetera, so on and so forth.
Considering I'm in the middle of a table build right now as part of said commissions, I thought I'd bring up the topic, and highlight some guidelines, based on my experience, for the working side of the commission relationship.