I popped to a little haberdashery to see what my options were. I nearly went for some teacher-esque corduroy ones, but settled on these faux-suede ones instead. Ridiculously, they cost more than the cardigan itself (£2 vs. €3.50!) but to me, it's well worth it! The cardigan should have been a lot more expensive - it's made from cashmere, and originally from Jaeger!
If you look at this photo, you can see how thin all the surrounding fabric is...
Attaching the elbow patches
Using iron-on elbow patches is pretty self explanatory, but I needed to deviate a bit from the instructions! Firstly, I had to sew up the actual hole, just to make the surface a bit more even. I also decided to make the patches a bit smaller by cutting off the edges (but leaving the pre-cut sewing holes in tact!). I think these patches are also designed for men's jackets, so are a little too big for women's cardigans.
When positioning the patches, I marked out where the tops and bottoms should go with pins, then made sure they were completely symmetrical before pinning the actual patch on to the cardigan.
Then all you need to do is iron them on, and for extra security, you can also sew around the edge!
Repairing old favourites is a great way to be a bit more environmentally friendly. The rest of the cardigan is fine, but cold elbows are no fun!