Here's another thing I found at Target years ago on clearance. It's just a brown cardigan that I was never crazy about. As I was going to bed a few nights ago I started thinking about it, and I decided to chop it up. Here's how it went.
First I cut off the sleeves (then hemmed them, of course). I don't have any short-sleeved sweaters, and they're probably pretty impractical, but I live in Texas, so I only wear the other kind a few times a year. I also don't love where it buttons. It feels like one of those super long cardigans that hipsters like to wear. (Just so you know, I use the term "hipster" almost indiscriminately. Don't be offended.)
When I first tried it on after chopping the sleeves, I noticed that it fit weird. Then I noticed that I wasn't wearing a bra. Let me tell you, it makes a big difference.
It just needed something extra along the neckline. I cut 1" wide strips out of the former sleeves, did a ruffle stitch on them (remember, highest tension and longest stitch length) and sewed them down to the neckline. I like it this way.