The process is easy, but it takes a good bit of time and a rudimentary knowledge of sewing. (You should know how to use a needle and thread.) And for method 2 you will need to know how to use a rivet gun, which is easy, and I learned how to do it myself. If you're really confused, ask an employee at the store you buy it from. Someone should know how to use it! (Rivet idea is adapted from this tutorial made by Luphinus and Diadexxus: http://dia.critter.net/tutorials/sandals/ . I recommend looking to that as another option as it is of a different design and is also time proven to work!)
Fursuit sandals will protect your suit's feet paws from damage and dirt on the ground, as they will take the beating and not your paws! They're pretty inexpensive to make yourself (about $30-40 for the main materials, a little more if you have no sewing supplies around at all, though generally you can find cheap needles and thread at the fabric store.)
For building the sandals you will need:
-Needle and thread
-Anti-Fatigue Flooring (you can get these at your local hardware store. I found mine in a really random place in flooring at Home Depot. Most places should have these.)
-Nylon Straps (one inch wide is good. I used about 120 inches of it, though I messed up, and ended up wasting another full 60 inch length of it. You can find this at a local fabric store.)
-4 parachute buckles (I found these right near the Nylon straps at the fabric store.)
-A lighter or some matches (some way to produce a small flame)
And additionally for method 2:
-Rivets (heavy duty are recommended. I used 3/16" / .5mm rivets)
-A rivet gun designed for the type of rivet you are using!
-washers that will fit the rivet snugly. (Ask for help at the hardware store if you are unsure. Again, the employees should easily be able to help you out! :D )
optional, but recommended:
-hot glue gun.
[be it noted that you should have fursuit feet-paws already made, this is just a tutorial for the sandals.]
See pictures here for your supplies