I've built myself this simple router jig that I have found very useful for my mission furniture projects.

When combined with a top bearing template bit and router, very precision cuts can be made in minimal time with minimal effort. Depending on the task, you may not even need to measure.

It can be made in a couple hours.

Modify the design to fit your own requirements. I'm getting ready to make a second one to fix some of width limitations of my first design. This one can only take 1.5" wide stock. I'd like to make one that can accomodate up to 3.5" wide stock.