The most important thing you can do for carpet is also the most important thing to do for upholstery. You need to vacuum it on a regular basis. If your vacuum has a hose attachment use it. If it does not, you can buy a good 1 galloon shop vacuum for a low price with an upholstery attachment. Remove all of the cushions and vacuum them thoroughly, taking your time and moving meticulously. Be sure to get into all of the cracks and crevices of the couch especially on the base where the cushions rest. Do this vacuuming at least once a month, more often if you have pets or kids. Another tip is to reverse the cushions often if you have reversible ones. Most couch cushions can be flipped over but seldom are. Flipping them over will spread out the wear over more fabric and keep one side from wearing out before the other. Flip the cushions once every month after you vacuum. The last tip I have is to have your upholstery cleaned on a regular basis. Clean it at least once a year if you have pets and kids. You might be able to go two years between cleanings if your home has low traffic. Cleaning it regularly will keep your upholstery from becoming permanently stained and wiull remove soil that would eventually wear the fabric.

As you can see, there isn't much to taking care of upholstery. By doing these three simple things though you will greatly extend the life of your upholstered furniture.