One of the critical aspects of building an electric guitar is the neck pocket. You want to get a very snug fit with the body of the guitar. The tighter the fit, the more sustain your electric guitar will have. Below is a photo of the completed neck pocket for my electric guitar.
Notice on the side of the neck is a pencil mark. This mark is just below the 16th fret. This is where I want the front edge of the guitar body to be on the neck.
Here is how I made my neck pocket for my electric guitar. Even though I had made my own template, I wasn't successful in making a neck pocket with a good tight fit. the problem I had was that the neck didn't fit snugly when the pencil mark on the 16th fret (photo above) was on the edge of the body. I noticed that the heel of the neck was slightly tapered, so I placed a pencil mark on the 15th fret knowing this would make the width of the neck pocket slightly narrower than needed. This would allow me to sand the inside edges of the neck pocket so that the neck would fit snugly into the pocket when the 16th fret was lined up with the front edge of the guitar body.
First, I drew a centerline the length of the guitar's body. Next, I placed the neck on top of the body and placed two pieces of 3/4 inch thick scrap pieces of wood on each side, and loosely clamped the neck and the body to the table as shown in the photo below. Loosely clamping the neck allowed me to make left / right adjustments to get the neck centered without losing the spot.
Next, I carefully measured on the far end of the photo, the distance between the centerline I marked and the edge of each board. The goal here is to align up the neck accurately with the centerline of the body of the guitar. To do this, measure from the edge of both boards to the centerline. Your neck will be correctly lined up when both dimensions are the same.
Once I had the neck properly aligned with the center of the body, I clamped down the neck tightly so it wouldn't move, as this will be its final location.
Next page: More Making the Neck Pocket