...So no matter who you hire, you'd better know what you want and need. I'm a contractor too (but I only build ponds at my house) and I basically run into 3 types of customers. Those who know their stuff but have no time or talent to do the work themselves

, those who know just enough to be dangerous... but are convinced they are experts

, and the ever-present clueless

. Unfortunately contractors tend to fit the same 3 definitions

.
If I was going to hire someone to build a pond it would only take about a 15 min interview to figure out how much they really know about koi-keeping. That would tell me what level of guidance I would have to provide for each part of the project. To me that is the key to any type of project. The homework done in advance is a good predictor of the final product.