Some basic ways to go:

1) Find a studio - Try to find a studio that has competetive Pro's teaching there. Not a studio with a closed door policy (aka doesn't allow independent teachers in), at least not without asking around about reputation. If they allow independent teachers to use the floor for lessons, I usually see that as a good sign, there's also usually a bit more choice.

2) Find a ballroom club - some college clubs allow non-students to join.

3) Go to group classes and ask around. If you see someone practicing in the mirror, ask them if they compete, and if they would be willing to talk to you. Find competative-style ballroom classes.

4) Shop for a teacher. Explain, from the get go what you want. Do they compete or take coaching, themselves? Skill updating is good. If you want to do Pro/Am, will they be able to take you on as a student? They may already have students in your age/gender/skill level, and battling for your teacher or chosen dances come competition time is not fun. Secondly, do they have other students that do Pro/Am, that really cuts down costs, as you split the teacher's expenses at competitions? If you want to do Am/Am, will they help to play match-maker? I have one male dancer friend, that's how he found most of his partners.


Good luck.