Purchase "Indoor No" spray from your local pet store.  If you do not want to spray it directly on your furniture, spray an old towel and place that on the couch instead.

Place foil on top of the furniture your cat should not go on.

If your cat scratches furniture, you can buy double stick tape that won't hurt your furniture.  Simply place it where your cat is scratching, and watch him give you a mean look when he attempts his first scratch!

If your cat jumps on the counter, put some pots and pans precariously on the edge.  When he jumps up, the crashing sounds will scare him off.

When your cat attempts to jump on the table, put him down immediately and say, "No!" very forcibly.

As your last resort, use a spray bottle filled with water to shoo him off of the forbidden spot.

Many pet catalogs sell items that will emit a startling noise and unpleasant smell when an animal goes where he shouldn't. This is helpful for kitties who jump on counters and other places you may not want them.

If your cat is jumping on or urinating on furniture, place mouse traps upside-down on the furniture.  Cover the trap and cushions with newspaper.  When your cat jumps on the couch, the loud snap will most certainly make him or her run from the furniture!