You are critizing him by thinking you are better than him, instead of critizing his ideas.
You need to change that inappropriate behavior in the first place.
Take the opportunity to challenge his ideas positively by asking
"why?" enough times. If the idea is so stupid, he will eventually discover it himself by answering your questions.
This technique has the advantage help you understand. His idea is probably more intelligent than you think.
seeking to understand before trying to be understood will help your boss disarm himself against you. When you propose someone something, its lizard brain will try to determine if it's a treat. His lizard brain want to him to be safe. Seeking to understand him will re-insure his archaic brain.
Now if you have a better proposal, I'm sure he will be more than happy to listen to you. Be prepared to be asked
"why?" enough times until he is convinced.
After all, you are the professional, that's why he hired you at the first place. He should listen to you.
If he is not interested by your ideas at all, there is only one thing to do: quit.