Man, I feel for ya as I think we've all "been there" at one time or another: whether it is a bad mechanic, contractor, plumber, or guit tech, poor workmanhip is --sadly-- not always evident right away, and often when it is too late that we have to live with the junk they've peddled! The primary reason I've learned to be a jack of many trades as best I can.
For a good tech (or luthier if you want to get into serious guitar work), I have weighed, in no exact order:
- word of mouth …vastly easier now in the internet age than decades past
- evaluated his finished work of other clients
- price: too good to be true often is the case (the guy who re-piped my house drives a nice Jag and Vettes ...he's worth every penny given the pricier and more frustrating alternative!)
- turnaround time (talk to me about a bozo who had enjoyed an excellent reputation in Santa Monica CA, and then jerked me around for weeks ...he's no longer in business, thankfully!!)
- personality: one who listens to you, is patient and willing to make things crystal clear, does not rush or talk above you (especially with "his vast experience" yada yada), one who is willing to state flat-out that he will stand behind his work or will make it right for you. As is often said with buying an old Porsche, you are "buying" the owner when you are weighing his car. This tech potentially will have my valued guitar in his hands; I want it right ...he should not be defensive, but empathetic to your love for the guitar.
Off the top of my head, anyhow. Also admittedly much more difficult the farther one lives from the beaten path. Not a perfect list, by any means, but it's a start. The one thing in one's favor these days is the web where you can not only judge reviews, but also potentially speak to past clients. Best to you!! And post back with what I hope to be a stellar result.
Edward