These are some defining characteristic of the product that you can feel free to use (or not) as inspiration:
1) They will have 3 strings, instead of 6.
2) They will be made of top-quality sustainable wood (as opposed to those cheap toy guitars anyone can buy at WalMart).
3) They will come in fun shapes, not just the classic 8-shaped guitar body.
4) Minimalistic design, natural wood finishes.
Ideally, the logo will capture some of these characteristics (feel free to be subtle, of course).
It should look good on wood (maybe a monochrome version) and over a white background.
Please keep in mind the end user (kids), the primary target (parents) and the secondary target (college kids, hipsters).
That's it! Best of luck and thanks so much for participating!