This isn't from scratch . . . but this is sorta funny. I got some custom P90's made by Clint Searcy, and when they came in the mail I wanted to hear them real bad, but no guitar to put them in. So I took an old Charvel neck, and a hunk of construction grade pic (2x12) and hacked out a working guitar in about an hour. I laid the neck on the body, traced it then cut the neck pocket freehand with the router. screwed the neck on and routed one hole freehand where a pickup could go. Screwed a flat bridge on, even drilled through the body holes for the strings and used ferrules! Wired the pickup with a volume, and that was that. Unbelievably rough, but it actually sounded amazing. Pine is a very resonant wood.