One of the fun things about building electric guitars is wiring them up. Factory wiring tends to be simple, minimizing the amount of fussy handwork required. Many manufacturers keep strictly to 'classic' designs, seldom if ever changing anything. These designs are generally simplistic, often crude or even stupid, and sometimes outright flawed. There is no need for you to do this. I don't. Here are some of the things I have done over the years. I don't claim to have invented any of this, although some of these schematics I have never seen anywhere else, and had to derive them myself.
The smaller single-tier guitar racks (above) were a modification of a standard sort of stackable little bookshelf that I have built quite a few of. The larger two-tier racks (below) were based on a similar sort of construction. Unfortunately, I never saved any plans for these things, in fact I never had more than rough sketches to start with, and improvised the rest. Once I worked-out all the dimensions and details for the first one, I just copied it. These racks are now a decade old, and have stood up to humid summers and dry winters perfectly. Nothing has pulled-apart or cracked.