Controlling where your cat ventures in your own home can be a nightmare if they have the habit of venturing on dangerous kitchen surfaces or threaten some of you prized ornaments.
There are some ways to train them to keep your cat away from certain areas of your house. One is to use the Ssscat! Automated cat repellent spray. The spray detects cats up to a metre away and releases a smelly spray the cats are adverse to. It's harmless and safe for you and your cat. After a while they will naturally keep away from the area as they learn it's better to keep away. You could use it for rooms that you don't want the cat visiting or areas with plants that you want to protect.
You may also try other scents that cats dislike including scented oils such as eucalyptus, citronella, lavender, lemon grass and peppermint. Just place them in the areas where you want to keep your cat out. You may need to experiment to see which of them works for your cat.
Cats also dislike the texture of some surfaces - try placing aluminum foil across and area you need them to keep off. The slippery texture is off putting for them. You could try this as a temporary measure so they get trained not to stay in that spot. After a few weeks you may try removing it and hopefully they will still keep off.