There's a school of thought that goes along the lines of "if you haven't started (or finished) that by now, you're never going to do it." I usually don't know what I'm going to do or when I'm going to do it and, unless I've got a specific deadline, the last thing I'm worried about is how long it's been since I got the idea or bought the supplies.
When I added the Eagle's Flight pattern to my Ravelry queue back in 2007, I had a specific yarn in mind. The whole reason I wanted to make those socks was because I had yarn in my stash similar to the one that designer had used and I loved the way the feathers looked in that mottled brown. I finally cast on back in September and wound up using a different (but equally old) yarn from my stash. The yarns are similar and it took me a while to realize that I'd changed my original plan.
Because I don't think it matters if my feathery stitch pattern is angled up or down, I switched to toe up and used my usual short row heel. The yarn is Patons Stretch Socks in Taffy. On Black Friday in 2008 it was $2.62 a skein and I bought it in every color they had in stock. This year, I'm happily using it up. Sock yarn doesn't have an expiration date and it was waiting for me to need it.
This post is linked to Crazy Mom Quilts and Patchwork Times.