Correct Way to Warn a Kitten

Siamese
Cats are very intelligent animals, and they clearly remember how you treat them, so don’t easily bully them. However, if they make a mistake, you still need to give a proper warning.
1. What to do if the kitten climbs on the bed?
Whenever she climbs on the bed, lie down facing her, stare at her, and make a "mm..." sound from your throat, which is the kind of warning sound cats make to each other when fighting or threatening.
That sound is hard to imitate but very effective.
Then raise your hand as if you are going to hit her; or simultaneously make a hissing sound while blowing air toward her nose.
Or extend your hand in a clawing motion, like cats preparing to scratch each other, quickly touching and sweeping over her paws, nose, and head; she will definitely be scared away.
— Of course, you should try to act like you are threatening and intimidating her (the more you simulate an adult cat competing for territory, the better). Do not make friendly gestures such as laughing or scratching her to show affection.