@Thomas,
That's definitely one I'm working towards... not yet, though. I've sketched her but am not ready to do a "real" portrait yet -- want to warm up more with simpler stuff. (I've found painting portraits of people I know to be the hardest -- I seem to "see" more clearly when it's people I don't know.)
This goes for animals too, happy to sketch your cat, TTH, that's more in my comfort zone. Just a quick sketch though (pencil probably), don't expect anything too impressive! Any photo is fine, but one that is clear and with a lot of contrast would be best.
I found that I'm out of watercolor paper so haven't done anything yet but am looking forward to Osso's exercise, I think that's just the sort of thing I need.
I seem to be set re: colors -- I tried to paint a (picture of a) house for a friend recently and my colors were really nice, my draftsmanship sucked though. So I guess that's the main thing I want to brush up on, a good clarification. Colors have always been easiest for me. I have to check which watercolors I have now, I used to have Windsor & Newton but recently got some new ones that are a brand I didn't recognize (recommended by artstore dude), I'll check.
Thanks again for all your ideas and nice to see fellow-artists getting inspired...!