From Knitty.com: This is the ultimate after-the-fact rationalization for your fiber habit! Turn your stash of 2-4 ounce batches of fiber in different colorways -- different fibers, even -- into something that looks like you meant to make it just like this from the start!
Start by knitting a stockinette panel from different combinations of color samples (see color combining 101). Once you decide on your final yarn, knit the remainder of the stockinette panel and the surrounding mobius edging from that yarn. Add some small areas of contrasting yarns from your stash to spice up the overall twinkle of the wrap.
Tip: To get the most out of your sample yarns, especially if you have lots of small balls, deal with ends by using a Russian Join. Fold ends from adjoining yarns over each other and work each end back through its own yarn with aid of a tapestry needle and running stitch, trimming ends after a couple inches. This allows you to knit with a continuous yarn.
Alternately, weave in ends using duplicate stitch. Both methods do a really good job of disguising ends so you can have a reversible fabric.