There are a few things you should look for when you're researching studios. First off is equipment. What your recordings need is a good signal chain. That means high quality preamps, microphones, ad/da conversion, and monitors. You can go with an all in one box like a boss or yamaha, but it will show in the long run. the preamps on such boxes are very limited. The actual mixing abilities in the all in ones are very limited. You will sound like a garage band. I had one of these for years, and despite our best efforts our band sounded cheap. I've spent thousands on gear so that you don't have to.

Talk to your recording engineer and see if it seems like a good fit. I am pretty selective on who I will work with, and you should be too. Does it seem like you connect? Do they understand your songs? Trust your intuition.

Listen to their samples. The proof for me has always been in the final product. Trust your ears.

There are a lot of studios out there, so look for a good combination of equipment, pricing that you can afford, availability, and location.