For me it depends on how far along I am with the project. If I just have a group of fabrics that I want to keep together I tie them in a bundle with a bit of salvage. And, of course, if there's a pattern it stays with it. For those projects that are actually "in progress" I put them in a "project bag" which can be one of those type from a LQS -- large 16" squares with a zipper. I've used my hole punch to give them some breathing space. Then I line them all up in a big clear box. For smaller WIP's, they are in clearly labeled shoe boxes. I have tons of small fabric "bars" in a shoe box that I am making rail fence blocks. It only comes out as an 'I'm bored' project. I also have lots of blocks stored in a rubbermaid 3 drawer in my fabric closet. I am still finding ways to organize but so far, so good.