The internet is full of advice for things a man should not do after getting married. My favorite is “don’t forget to tell her you love her”. Of course there are many other obvious things, like don’t stay out all night with friends, don’t see old girlfriends, and don’t lie to your wife.
A few of the more less obvious tips include don’t assume you can have sex whenever you want, don’t expect your wife to do all the housework, try not to belittle her family and friends, and don’t pay more attention to your cell phone than her, especially when she’s is talking to you.