The first thing I think of when I think of stash busting is a really big blanket. I guess that’s because I’m working on a really big blanket, and have been on and off (mostly off, admittedly) for about a year now. It’s in strips that are 6 feet long, and I’m hoping to make it 6 feet wide, if I can stand it that long (there is no worry of running out of yarn before it’s that size). It will be massively huge, heavy, warm, completely unwashable and awesome. And it will use a lot of yarn.
I guess that’s the main reason afghans and stash busting go together, because they’re a great way to use up a lot of yarn. You can make individual squares with the different colors, or just let it stripe, or make log cabin blocks and sew them together. (Speaking of log cabins, check out the Parcheesi Afghan by Janine Bajus, which combines log cabin squares and garter stitch borders.
You don’t really need a pattern for a project like this. It can be as simple as knitting long strips and sewing them together when you’re done (as in this project, Blankety-Blank, from Completely Cauchy), which has the benefit of being more portable than my join as you go method. If you want a slightly more organized look, try the N² Imaginations Stashbuster Afghan.
Mitered squares are another great choice for stash-busting, because you can make them small or large and they’re really portable and easy once you get the hang of the shaping. The Stained Glass Mitered Afghan by Joan L. Hamer is a beauty and a free Ravelry download.
Looking for a shape that’s not quite square? Why not knit “squares” that are shaped like fish, as in this project from April Broken? Or try Frankie Brown’s little buttons, which are still square but are filled with fluff to make a puffy blanket. (Frankie also has the amazing 10-Stitch Blanket, which is worked in a squareish spiral so that you never have more than 10 stitches on the needle at a time.)
If you want to get really crazy, check out the Oddball Sampler Afghan by Sarah Bradberry, which is made up of all sorts of different squares.
And if you’re willing to pay for a pattern, the beekeeper’s quilt by tiny owl knits is a classic with its puffy hexies. Lee Meredith also has a cool-looking project in her Color-by-Number Stash-Busting Blanket, which uses fun tricks for minimal finishing.