After drooling over GregGriffin's g10 fins,I decided to order a sheet to make some fins for myself. No wonder his fins are so sweet - a blind monkey could foil this stuff sharp enough to fillet a fish! Seriously you should try some for your next board - it seems kind of pricey but you can get a 12"x24" 1/4" sheet for about $60 and that will net 3 sets of fins so for the price of one set of fiberglass fins from the surf shop - you can have three that you made yourself! Just google g10 frp4 fiberglass sheets. After doing some wooden fins and some fiberglass fins from panels I layed up myself from 6oz, this g10 was really a treat to foil!
Here's a couple tips I used for these:
Get the grit blade for your jigsaw to cut this stuff out - i got one from greenlight for like 5 bucks!
After cutting out the fin template, tape up the flat sides of the fins and spray over the tape with adhesive then stick the fins together and foil. The tape will show a centerline to work towards and it will make unsticking the fins easier and you will not have to sand the flat side to get any adhesive off - just peel off the tape. This method helps to keep your fins symetrical.