What to consider:
1. Focus on adults. If there's a ballet studio with big focus on adults in your town - this is exactly what you need. Teachers in such studios are experienced in working with adults - and it's very different from working with kids or professionals. You can also go to a kids ballet studio where they have adult ballet as a side thing. But you need to understand that in this case the level of teaching won't be so high.
2. Teacher. Finding a good teacher is the most important thing. The teacher doesn't only need to be a professional ballet dancer, but also to be qualified to actually teach the discipline. Or, at least, to have a big interest and experience in teaching adults. Special qualification and experience in teaching adults mean that he/she is genuinely intrested in the matter and will always motivate you a lot at classes.
2. More than one option. We recommend trying several studios to compare and choose the one where you will feel most comfortable. The thing is, you will not be able to understand right away what ballet will mean for you. Maybe you will "fall in love" with it and will want a more demanding and serious kind of teacher. Or maybe you will go to classes because you like that special atmosphere and beautiful gear - and you will want a soft and easy approach from the teacher. Go to a few classes in several schools. Don't rush to conclusions, give yourself time to figure out what suits you best.
3. Performing possibilities. Nowadays many studios organize so called class-concerts for their students or even put own shows, where their students dance. Even if all this stage thing seems too far away, we recommend choosing a studio where there is such a possibility. If a studio organizes performances for its students, it means they approach ballet training for adults very seriously. Moreover, there's a high chance you will like ballet so much that after some practice you will really want to go on stage.
4. Ballet floor. Ask upfront if your studio has professional ballet flooring. You might think that any floor is good for ballet, but that's not true. Special ballet flooring makes sure you don't slip on the floor and fall while doing exercices (especially in the center) and (very important for beginners) feel very well how your feet work.
PROFESSIONAL BALLET FLOORING AT GRAND BATTEMENT BALLET STUDIO IN MOSCOW, PICTURE FROM THE OFFICIAL INSTAGRAM ACCOUNT OF THE STUDIO.