Over my years of guitar making, I have settled on a set of design and construction features that I like to incorporate in most of my instruments (but it's fine if you want something custom/different - I can usually oblige), as follows:
a) Multi-piece neck construction. For efficient use of wood, plus neck strength and long-term stability, and of course, the aesthetics.
b) Mark Blanchard dual-action "geared" stainless steel truss rod (except classical guitars, where I don't need one!), usually mounted so it's adjustable from inside the guitar body.
c) For steel-stringed acoustic instuments , two carbon fiber rods, either side of the truss rod.
d) For classical or other nylon stringed instruments, one carbon fiber rod down the center of the neck (no truss rod).
e) Mortise and tenon neck to body joint with a minimalist heel.
f) Kevin Ryan laser-cut A4 linings. Kevin kindly granted me a license to make and use his patented design 4-way bendable linings.
g) Laser-cut braces with weight relief holes in the appropriate places.
h) Triple-top soundboards with minimal or no bracing. I make a sandwich of three layers of soundboard wood with the outer layers being about 0.05" thick and the inner layer about 0.08" thick with a laser-cut honeycomb weight relief (much like you'd find in a double top that uses Nomex). I don't do this on all my instruments, just some. I can do traditional soundboards and bracing too!
i) UV cured clear polyester finish (from Cardinal). This stuff is hard, ultra-thin (hardly affects the sound from in-the-white to finished), and polishes to a mirror finish.
Much more to come in this section soon!
Here are a few panoramic views of my workshop - these were taken some time ago, prior to the addition of my spiral staircase: