I've seen people completely trash their carpets in their houses, or go barefoot during some workouts-YIKES! Especially on workouts such as Plyometrics, proper form, proper shoes and the proper surface make all the difference. A glucosamine supplement can also help if your knees are extra stiff. This video explains alot of that.
Also-This is a picture similar to what I work out on. I would recommend nothing less than a 4X8 section of blocks, which luckily for me, came in one package ($20 bucks at Sam's club-but you can get them in a variety of places) and can be put away quickly, or just kept where you want it. Make sure you have carpet gripper underneath, you don't want to slip slide away while doing plyo on these things! You'll also find that moves like the "Dreya Roll" and many others are much more comfortable on your spine and you'll just feel more comfortable working out overall.