The first step is to identify which plants in your home are toxic to cats. There are a number of resources available online and in libraries that can help you with this.
If you have any toxic plants in your home, the best way to keep your cats away from them is to remove them altogether.
You can use chicken wire, fencing, or even plastic sheeting to create a barrier around the plants.
There are a number of commercial plant deterrents available that can help to keep your cats away from your plants.
You can also train your cat to stay away from plants. Start by teaching your cat a command, such as "no" or "away."
It may take some time to get your cat to stop chewing on plants. Be patient and consistent with your training, and eventually your cat will learn to stay away from them.
If you're having trouble keeping your cat away from plants, you may want to seek professional help from a certified animal behaviorist.