The Costco Quilt. A classic from the Internet’s lightweight camping scene. After the ZPP kit I wanted to try my hand at something more functional, but still fairly cheap and straightforward.
The basic premise of the project is taking a down throw/comforter sold at Costco and turning it into a quilt you can take backpacking. It’s super light, reasonably warm, and easily stuffed into a backpack. The quilts are sold in two-packs, which some take advantage of to double-stuff the down in their quilts. I did not.
A good tutorial on the process can be found here.