How do you determine which wineries would be best for our group?

Rave reviews from previous tour groups.
Smaller, non-touristy locations
Excellent wines, moderately priced
Warm & friendly service
Perks available (cave tours, barrel-tasting, wine-maker available, etc.)
We try our best not to visit wineries whose tasting fees exceed $20-$25 per person, though this is not always possible.