The traditional rating "standard" consists of
1) Looks
2) Service
3) Attitude
..and are loosely graded from 1-10, 1 being the worst and 10 being the ultimate.
Personally, I don't feel comfortable describing people that way...like grading a cut of meat....but then again I happen to prefer a girlfriend/relationship type experience...so my attitude is going to be probably a little different than say, a felow who is arranging the "entertainment" for a Stag party, or that of a sailor who's just gotten his first shore leave after 6 months. Or a bloke who's just returned from Thailand and expects a gorgeous nubile vixen to walk on his dick. Or....