When you are together, expect pressure (whether it's because you have issues to discuss or not).
Don't spend so much time agonizing over and planning out your time in concert that you forget to enjoy it.
But simple companionship and connectedness is often the meat and bones of a relationship – and you still have to prepare yourself for the absence of his or her warmth, smile and all the wonders of non-verbal communication.
When a boyfriend and I were separated for three months, I drove him absolutely crazy because I needed – non-negotiably – to talk to him each day.
For instance, unless you're looking for a casual, non-exclusive relationship, at some point, one of you is going to have to move.