Yes, I'd be happy to share what I have learned.
No one is perfect. We are all flawed.
Communication is key. If you cannot have a heart-to-heart with your SO, you don't really have a good relationship.
You need to be patient and kind even when you don't want to.
Don't treat your friends better than you treat your SO. Don't put them down in someone else's presence. Don't make "jokes" - oh hey, just kidding - with them as the punch line. That's not cool.
If you can't say something nice, remain SILENT.
You have CHOSEN this person as the person that you want to be with right now. Act accordingly. If your feelings have changed, talk to them about it. Chances are they have noticed that you are treating them differently.
Remember why you chose this person to be with and rekindle that part of the relationship. You used to go to the movies with this person every Tuesday night and then to dinner and now you don't. Why? What changed to make you stop? Now, work on that.
OK - that's all I have for now. Oh, there's one more thing. If you feel like cheating, just don't. You're not "free" until you have tried to work things out - decided it wasn't meant to be - and then broke it off.