I completely forgot that cats scratching furniture was an issue until the other day Janelle strayed from her two scratching devices and started going at the bed. Most of the time, she is good. And if you don't have a cat that is good then here are some good options.
Cardboard Scratching posts that my cat can just jump on and start scratching are absolutely perfect. They come with cat nip, but I just put the cardboard down on the ground and she just jumped on and went at it. They last quite a while too. Ours has been beat up and we had one upstairs and one downstairs, but now we just have one upstairs and downstairs we have...
A scratching emery board. She doesn't like this one as much but it came with this feather toy that she plays fetch with. The emery board also files down her nails when she scratches into it.
Before we got these two scratching devices Janelle would climb on the sofa and scratch the arms of it as well as the side of the bed, but she really really enjoys the scratching posts and I am sure that this alternative could really help someone out there who has a cat that loves to scratch. Scratching is a normal cat behavior, there's just places that cats shouldn't scratch and so giving them surfaces dedicated to them scratching is great.
The cardboard scratching post was $4 on sale at PetCo and the emery board was a gift.