Originally Posted by Serum

I use M3, M4 taps, scroll saw, rasps (different grades), dremel, drills, scotch brite/waterproof sanding paper, calipers, ruler and some patience.

Easiest thing to do is to draw something, and print it 1:1; that way you can simple put the 'template' on the aluminum with double sided tape and cut away the stuff that's in the way.

A vice is a handy tool too. As is a press drill, but you can manage without both.

you are able to make parts like this fair easy;