Talk on phone mostly, once to thrice a week (last time IDD call very expensive). E-mail, ICQ.
Don't allow your mind to get too imaginative, otherwise you'll get too suspicious of everything your partner does, the people she hangs out with, etc.
Don't go and question her on everything she does, where you go last night? Who who? For what, etc? Possessiveness is not equals care and concern!
And both of you will still need to get on with life, have your own circles of friends, take up a hobby, etc. Don't take each other for granted, but don't let the fact that you miss each other get too much in your mind.
In otherwords, keep your mind healthy and positive. I know say is easy. Our r/s nearly broke down several times, but somehow we managed to see it through lah.