1. Definitely put your sweaters in pillowcases or some sort of bag - they shed A LOT. I read that tip a couple places, decided to use it, and was very glad I did ( the pillowcases had lots of fuzzy bits inside after it was done).
2. Consider going to a laundromat, as it says in the Etsy post - I'm not sure, but I figure they run a bit hotter and faster, and might felt the sweaters quicker (it took a couple few times for mine to felt properly).
3. Pick thinner sweaters - I had one that was a Christmas sweater with images, and it was thick from all the colors of yarn. It felted, but didn't seem to go all the way through the way some of the thinner knits did.
4. Ribbing doesn't felt well, even if it's 100% wool (unless the tags were lying)
So, now for photos. Here's a couple of the sweaters before I felted them:
And here's some things I've made so far. I've been enjoying needle felting designs for iPod/cellphone/camera cases - it's something different from needle felting 3-D objects. And it's easier to sew stuffed animals/figures with felt, since the edges don't fray. To put it simply, I'm loving working with felt, and I love felting old sweaters, since I get all sorts of fun and unique textures, colors, and patterns.
Sorry for the blurriness - it gets dark so early, I ran out of time for daylight photos, but I wanted to post these today. Better photos and posting on Etsy coming soon.