The design of a guitar headstock gives the instrument a lot of personality. Headstocks typically follow in the footsteps of a few classic shapes, but some manufacturers pride themselves on unique and extreme designs. Several small factors of the design can actually have big influences on string tension, tuning stability and resonance. You can redesign any guitar headstock, but using an uncut "paddle" template is your best bet for long-term wood stability.
Make a basic sketch for your design by choosing how many tuning keys will be on each side of the headstock. The most common choices are six in line, three on each side and four by two.
Refine your basic design by deciding on whether or not to angle back the headstock. Designs that are angled backwards away from the guitar's nut put more downward pressure on the strings, which means that you do not need to install a string tree. Look at Les Paul-style guitars for an example of this method.
Choose where to place the tuning keys on your headstock. Keep the strings' paths through the nut and to the tuning keys as straight as possible to avoid bunching in the nut slot and to increase tuning stability. Consider using a locking nut on designs that have very sharp angles off of the nut.
Add any logos or decals to complete your headstock design. If you just want a single-colour finish, then auto detail shops are a good place to look for professional work.
Locking tuners will typically require additional routing on headstock which must be accounted for in the design process. If you have access to AutoCAD or other design software, then try using it for your headstock. However, good sawing and sanding skills can make up for inaccurate or hand-drawn templates. Practice cutting your design onto some scrap wood before you cut the real thing. For inspiration, visit a local guitar shop and study the headstock designs you find. Ask if you can trace a few of the headstocks at the music store. The easiest way to get a rough template is by copying a few designs that you like onto drafting paper. Salesmen may be more likely to let you trace the designs of cheaper instruments.
Have a patent attorney check your design before you use it on mass-produced guitars. Do not paint over your guitar's serial numbers if you're redesigning an existing headstock. If your design requires you to cover the serial numbers, then consider getting the same numbers engraved on your guitar's neck plate. Large headstock designs may make a guitar top heavy. These kinds of guitars can be difficult to balance on a guitar strap.