Anyone got any tips on how to do this?
Ok, how about, how should I choose when I have no idea who the hell I'm going to fight.....mainly an RP character, I'm stumped.:confused:
Choosing Anatomy Expertise/Masteries.
If I was going to be mainly an RP char, I'd go as defensive as possible. So choose staff/polearm, or both staff, or both polearm.
if you're good aligned, choose evil races, vice versa
What if i'm neutral? 
It's such a middle of the road character really, I was just wondering if I should pick for the power combos, or wait till 50 and see who bothers me.
then evil races, waiting seems like a good idea to me, i never pinned a monk or blademaster tho, but chances are you won't have to worry about goods attacking.
OMG, wow.
I completely read that title wrong. Hahaha. I thought you meant WEAPON masteries.
If you're neutral, I'd go elf/drow, and of course, giant.
Seems most evil/neutral/goodies are either elf, drow, storm, stone, or fire giants. And they usually all have power combo related classes.
I agree with Jibber. Elf/Giant would appear to be the closest to a 'catch-all' anatomy choice given they are pretty popular races, if that's how you're thinking about selecting your anatomies.
Dey
If you're considering going Watcher, you may want to save a slot for unique.