Last night, I was trolling around on YouTube and found this video by Suzi Dennis. Her technique is to layer tissue paper on top of collaged papers and things, and keep doing several layers, so it looks kind of washed out and vintage. Then, you can cut it up and use parts of it in your collage projects.
So, this morning, I thought I would give it a go. I really like the finished product, but I think I would like to do this on a canvas or board, as a finished collage piece. I might play around some more with it, though, and see what I can do with it. By the way, the orange piece on the right is part of a mesh from a bag of oranges. I like having it encased with the tissue layers - it gives it a really cool look and feel!