I wash it all with my regular laundry. If it looks like it may bleed, I wash it by itself or with like colors. I usually put small pieces in a mesh bag. I use the regular cycle, regular amount of laundry soap and I may or may not use some vinegar in the rinse cycle. As a general rule, I don't use fabric softener. I dry large pieces in the dryer with the regular laundry. Smaller pieces, I usually steam it with the iron. (It's already wet so I don't have to use water.)
Basically, I treat the fabric the way it will be treated after I have made it into something.