Most of my backings are from fabric in my stash. I have one section just for backings. I also coordinate it to match the front but I don't think you have to or else type of thing.
I've also pieced backings and it's fun! You get another design to look at.
I like to buy extra wide backings on sale so I don't have a long seam to deal with but I have done that too.
Don't any any tips on quilting b/c I'm practicing FMQ right now.
Good luck! :D:D