Actually, I've come to the conclusion that the point of fishing in a typical short term survival circumstance isn't to catch fish, it's to entertain yourself and keep you out of trouble. If you do happen to catch something, great, but it's a luxury. YMMV...

So, that sort of flies in the face of your goal, unless the making of the gill net is the choice for keeping yourself busy. <g> BTW, they take a good deal of time and effort if you've never done one before, so not something you would do to allow time for some more critical survival chore.

For gill net making instructions, just check out the fishing section of many military survival manuals, for example:

http://www.equipped.org/fm21-76.htm
http://www.equipped.org/fm3-0570.htm

A good project for long winter nights if you've got nothing better to do with your time, perhaps, but from a practical perspective, if you really want a gill net as part of your survival kit, they are not very expensive, weigh little and vacuum pack down very small. I've carried one for many years in my personal aircraft kit, though it'll be left out on my next repack as unnecessary.