I'm often asked for help with training cats that are aggressive or timid. For timid cats, I usually suggest bonding play. I've written elsewhere on that. For aggressive cats, I usually advise staring them down, pushing in rather than pulling away when they bite, and clicker training.
Clicker training was developed by Karen Pryor. She developed the clicker technique while she was working at a marine park and needed to find a way to train dolphins and whales while they were underwater, so they would do their tricks. She settled on the clicker because it worked. She found that the technique transferred to her pets and that it works on all animals. She started training the trainers and then began her website. You can find a lot more about her on her website. You will see her stuff all over the website, because I've tried this and it REALLY WORKS!
Karen found that using the clicker added to the bond between the animal and the trainer. Most pets respond very well to training, but most owners don't know how to train their pets. Bonding is increased, intelligence is increased, and animals and their pets are happier when the pet is trained.
So, how is it done? First you need a clicker, next you need some really good treats. Freeze dried liver or salmon seem to work best, but some cats prefer poultry.
Once you have your tools ready, catch your cat doing something you want to see it do more of -looking before attacking, but not attacking; walking away from the plants instead of eating them or going potty in the pot. Something you want to see more of, whatever that is.
Click to mark the good behavior, name it to your cat, then give your cat a treat and a cuddle. At first, the treat is the thing, but later it will be the click that marks a treat coming. Finally, just the word.
When you begin a training session, you will continue for 15 minutes and then stop. Your cat gets 1-2 of these sessions, and it will often have the behavior down. Continue in 5 minute sessions to reinforce the behavior once a day, then go to once a week. Once you are in weekly reinforcement sessions, you can add another behavior with another word. Keep doing this until your cat knows lots of words and behaviors.
Next, begin to combine behaviors, say: "stand," "bat," "meow" and then give the click and the treat when your cat does them all. Now you are training your cat to stand on hind legs, bat the air and meow. Perfect for a cat food commercial! Or at least a cat toy commercial! So, that's how you do it. For a lot more on "keep going" signals when your cat is almost - but not quite -doing what you want, read about Operant Conditioning.