My 11 month old is the same.
I say to him no and then pick him up and put him somewhere else.
When he crawls back, I pick him up again and keep him at eye level while I say no and put him back down away from where he was being naughty.

They’re never too young to start learning what no means.

Just keep doing what you’re doing, saying “NO!” In a firm voice. It’ll take awhile for him to learn and listen, he’s just a baby

Keep using your firm voice and remove him from the situation – even if you only take him into the next room.

Personally I would not use the cot following bad behaviour. Your child won’t want to go in the cot at sleep time if you do. It will be seen as a negative place not sleep. I made that mistake myself. When she started talking she would tell me “I don’t want to go in my cot, I haven’t been naughty”

He sounds like he is playing his own way and the tone of voice and strictness is a good idea so that he knows what is wring now . I am very repetitive and don’t give up so I don’t care if I say No all the time because it wont change. I’m sure he will learn very soon .

I’ld stick to the change in tone of voice and maybe add a kind of time out where you ignore them for a short time

I would make eye contact with him & in a stern voice say ‘NO’. Make sure that he knows that you are serious. It does take a while for the little ones to realise but it does work.
I have done the same thing with the 5 of my children …… It takes time but it does work in the end. Good luck

Tell him what he is doing wrong in a firm voice and then give him an alternative on what to do.
“Stop, don’t pull my hair, it is not nice. Why don’t we play with blocks instead”
I have always used that approach and my son is very responsive and learns very quickly.

if he is very naught you could put him in his cot.

surely it is just a phase

there are some good comments here

have you work out a way yet?

Have you had any luck yet?

When my daughter pulled my hair or went to hit me in the face, I usually just gently grabbed her hand and stroked my face instead making a pleasant humming noice showing her that I really liked being gently stroked. We have to understand that they are not doing this to hurt us. So saying no and showing the ‘right’ way is probably enough for now, and when he is a bit bigger you can enforce a time out or whatever method you choose. I am totally against any kind of smacking or ‘tapping on the hands’ as I don’t see how we teach them to do the right thing by doing exactly what we tell them not to do. Good luck!