I think punishment is the wrong approach. What you are trying to do is reward him for good behaviour, and extinguish bad behaviour. And if he is not behaving well very often what do you then?
First read How To Talk So Children Listen. It challenges the whole behavourist approach and replaces it with things like distraction, intervention, involvement, pre-empting triggers, consequences (but in a child centred way rather than just threats and punishments) It was written for NT children but I think it works brilliantly with ASD too, because child feels secure.
But I think there are exceptions, where you have to act more ruthlessly. A good example would be if your child hits someone. The ASD course I went on, emphasizes total extinction for violent behaviour. So even though you know your child is very upset, and that is why he is hitting, or is experiencing some sensory overload etc, you take the line that you want to EXTINGUISH that behaviour. So whilst I used to comfort/excuse my son (now 10) for hitting (not that often but getting worse as his frustrations increase), or tell him off, or threaten no telly, or send him upstairs angrily, I now do the following (and you can imagine a 10 year old is quite difficult to discipline)
I go up to him. Take him by the hand, and remove him from the room immediately. I don't argue with him, I don't discuss his reasons for it, I don't comfort him for being upset, or give him a sugar lump or such like, or ban him from telly for the rest of the week, or scream that he is not allowed to hit people. All this is going to up the anti. But he knows I have responded immediately and he is not allowed to continue that particular behaviour which was presumably giving him some satisfaction
Above all I don't raise my voice, I don't get upset, I just ACT. He stays in his room for 10 minutes. And he knows hitting is unacceptable because I react so quickly. What I don't do is rant and rave and explain things to him, he just knows he is not going to get away with it in any context. And he doesn't want me to be so cool and uninvolved, he wants me to get involved, so being detached is a way of "punishing" him, if you like, although I prefer to call it extinction.
But if you read the book you will see that what you are after is a situation where the child doesn't need to hit people to express bad feelings, because you are allowing him communicate in other ways.
Ditto throwing things, you replace that with throwing things that are allowed, or messing things, you replace that with messy stuff that is allowed etc etc.
My child is HFA, but I suspect this is true of relating to most children whether ASD or not.