I posted this on the facebook page, but just in case I'll post it here also. Tandy sells a kit, Gunfighter or Gunslinger, can't recall the actual name. Anyway, it's pre cut and pre drilled. All you do is fold it and lace it. The thing is, you can adjust the belt loop for a higher or lower carry, but you will have to drill some holes if you want to adjust it.
By wetting the leather you can form fit it to your Ruger. Wrap your Ruger in Saran wrap, wet the leather and keep working and squeezing the leather until you get the shape you want. Wet the belt loop so you can obtain a very tight crease at the top. You can use clothespins to hold the holster edges together until it dries, or you can lace it wet.
I bought this kit back in October or so, more for a pattern than the actual holster. Using it for a basic pattern, I've made holsters for my '51 Navy, '60 Army and both '47 Walkers. None are artistic by any means, but they work for what I wanted. My goal was to make something that looked like what a cowboy would have made while sitting around the campfire or bunkhouse at night.
From what I learned with these, I've managed to build three that will hold a scoped S&W .22A, one for me, one for my son, and one for my son-in-law.
The actual making of a holster isn't all that hard. To make a pretty one though, well, that's above my artistic abilities.