What advice would you give a customer looking to hire a provider in your area of work?
Be sure you hire a piano technician, not just a tuner. (They don't have to use the word "technician", necessarily, but they really need to know how to make repairs and adjustments on your piano as well as tuning. Many times there are small but significant repairs and adjustments that need to be made before tuning should be done. If a string breaks during tuning, and they can, your technician will be able to repair it. I can do that for you, some who only tune cannot, or won't. It is also important that they understand how to inspect the whole piano. By that I mean, if you never see them remove the bottom board to inspect the bridge or adjust the pedals, then likely, they are only interested in tuning.
Also, I would say be sure your technician has experience and is attempting to stay current in the field of piano technology by being a member of the Piano Technician's Guild, for example.