I'll second the motion of Stohlman's Making Leather Cases book. One of the three publications has a pattern for a fly wallet that has pages to wrap the leaders to.
Also, if you really really want to do some nice stuff get the small book called Lacing and Stitching for the Leathercrafter. Hopefully they still make that one. I'm sure you can find lacing and stitching tutorials on yootoobee if you look.
I have made a few fly wallets but I don't like using them. I like making gun rigs, and I end up using the plastic pill boxes for flies.
li
btw, a fun place to look for stuff is the upholstery supply store. There's one here near me in the PHX that has manly stuff like seatbelt webbing and 2" velcro for a buck and a quarter a yard, and all the little snappy clippy things you cant' find at the fabric store.
It's.....Just....A.....Stick...!!