I'm very excited other people want to see how to make the Pixie Moss. When I showed it to my neighbor she said: "Michelle, you are a kook. I mean that in a nice way." We are friends, so I know she appreciates my funny craft adventures. I have many other slightly off-the-wall ideas that I will probably share over time. I'm just warming you guys up for now. So I'll start on the tutorial in the next few days.
Today I want to share some places to find the hardware for the messenger bag strap and one idea that might be really interesting, but I haven't tried it out yet...
First, let me just say you can make the strap less than 1.5", but I find the 1.5" width most comfortable. 1.25" would probably work ok too, but 1" seems to start digging into your shoulder if you put a few heavier things in the bag. For this bag, don't go wider than 1.5" or it won't fit the sides.
Many fabric stores will carry the two pieces you need (slide and rectangle ring). UPDATE 9/25/12 - I carry slides/rectangle rings in both black and nickel. The slide might be called a strap adjuster, buckle, tri-bar. The rectangle ring could go by rectangle loop.
Ok, about that idea--what about using a vintage belt buckle for the slide? If you can get the metal thing off in the middle, a belt buckle would probably make a really cute slide for your bag strap. I think these buckles would be fabulous on a strap!
Vintage Belt Buckles ~ Available at OldWaysPastPieces