I have been looking for a good mechanic to do some work on my car. I want to find one who will not make things worse.
Mechanic
A mechanic is an artisan, technician or skilled tradesperson who uses tools to build or repair machinery.
Duties.
Most mechanics specialize in a particular field, such as air conditioning and refrigeration mechanics, auto mechanics, bicycle mechanics, boiler mechanics, general mechanics, industrial maintenance mechanics (millwrights), motorcycle mechanics, aircraft mechanics, bus mechanics, truck mechanics, diesel mechanics as well as tank mechanics in the armed services. 
A mechanic is typically certified by a trade association or regional government power. Mechanics
read, somewhere, all over the world. "I don’t mean to do it. I just want to write. But people respond to the power of literature. It's a dangerous thing: you can sway people by the power of language and make them do things according to your will. I don’t want to do that. But my work, written decades ago, is used in some anthology or collection, and I have discovered that things I say are counted on by some people today" (Selzer