Recommendation, Advice, Warning, Order, Instruction

You might want to cut your hair.. good :)
You might not want to accept his propose. proposal
You could choose the blue jacket but in the gold colored.

You should try a spaghetti with salted cod roe sauce in Japan.
You shouldn’t make noise when you eat spaghetti. good :)
You ought to know that the car you can see in the rear-view mirror is an undercover police car.
I recommend giving chip tip when the nakai-san (waitress) came comes to your room for the first time in ryokan (Japanese style hotel).
Why don’t you go to the bathroom before going to bed?
It’s a good idea to add apple and honey to when you make (Japanese) curry.

You had better keep inside of the yellow line at the station. good :)
You had better not show your snacks or drinks in front of monkeys. good :)

You have until monday monring to finish the job until Monday morning.
You need to give me some bucks to pass this gate. (correct, but not natural sounding way of using "bucks")
You can’t use loud speakers in the library. good :)

You must pay tax. good :)
You must not use your phone while driving. good! :D

よくできましたよ！