It all starts with communication it seems. If you can talk with your partner then you can do all sorts of stuff in your relationship that so many never even know about. Getting close and understanding each other is important and without a great form of communication that's likely never going to happen. So above all else you should have great lines of communication with each other for the best relationship.
Another really important part of a good relationship is learning to accept each other as you are. Sure you can hide your flaws and attitude but sooner or later they will come out and you don't want this to be a danger area for your relationship. Of course, you can't show your crazy on the first date but sooner or later you will need to share your flaws and such with your partner. Once you can be yourself and they can be themselves things are so much easier and relaxed. This can also open up conversations that you never knew you would have.
Taking your relationship from one point to another can sometimes be tough but making sure you're doing all the right things in the relationships. If you think your relationship may be in trouble be sure to take a look at Luckybs and some of the posts they have about relationships.