The best way to ensure a long distance relationship is going to work is if you have a strong foundation to begin with. If you're both committed to making it work and understand the challenges inherent in a long distance relationship, you're well on your way. If your relationship is rocky to begin with, staying together while miles apart is going to be much harder.
Know the RulesBefore you enter a long distance relationship, it's best to spell out the rules around monogamy. Even if you were in a committed monogamous relationship when you lived in the same town, don't assume the same rules are going to apply. Even if the topic is uncomfortable, it's important that you bring it up and that both understand what you expect from the other.
Stay in TouchWith email, instant messaging and free long distance plans staying in touch is easier than ever. Take advantage of the technology and let her know she's often on your mind. Text her. Sign up for Skype or another video conferencing service and you can see each other when you talk.
Know When it's Going to EndMost couples see the long-distance thing as a temporary condition. Eventually they want to be in a place where each can live together. Maybe you're apart while she's in school or in the military. Have a plan and discuss what is going to happen at the end of that commitment. If one of you has to move for a job, decide in advance how long you will live apart--one year, six months--compromise and come up with a solution that works for both of you.
If you don't have a definite plan, one of you may feel that the other has the control over your relationship.
Bi-National CouplesBi-national couples are the exception here, of course. In the United States and other countries who do not have welcoming immigration laws for gays and lesbians maintaining a bi-national relationship is difficult. Even though you may not have a plan for when you can be together permanently, these other tips can help your relationship too.
Have your own interestsBeing in a long distance relationship you are in a unique situation where you have a lot of freedom that other couples may not have. Sure, sometimes you may hate that you have so much, but make the most of it. Get involved in your life. Take part in activities that interest you, start your own business or take up a new hobby. The time you spend will not only help the days go by faster, it will enrich you as a person and make you a more interesting partner. If you're in a bi-national couple, throw yourself in the politics of changing immigration laws to be more gay-friendly.
Curb JealousyJealousy usually doesn't do much for a partnership, and it's especially true for a long distance relationship. If you can't trust your partner, then this thing is not going to work. If you're always worrying about who she's with and if she's being faithful, you're not only going to drive yourself crazy, you're going to drive her away. If you can't get a handle on jealousy, either end the relationship, or seek help for yourself.
Be AccountableBe trustworthy. If she says she's going to call at three, be there at three to get her call. If you normally talk everyday at the same time and you know you're going to be bowling one night, be sure to tell her so she's not inventing all kinds of stories in her head.
Have datesEven if you can't see each other as often as you wish, take the time to have phone dates. Watch a TV show together or have phone sex. Share a bowl of ice cream on the web cam or read the same book. It's important to stay connected in any way you can.
Be RomanticSend care packages, photos of the cat and sweet love text messages. Email is good, but hand written letters are better. Get creative and send her little things from your day: a napkin from your favorite deli, a jar of jam from the country market or t-shirt that you slept in. Make her a mixed CD or write her a poem. Any little thing to let her know you're thinking of her.
Be HonestWhen things get hard, talk about it. If you're having doubts, talk about it. Don't let the distance keep you from bringing up the hard stuff. You're in a relationship, your relationship is not "on hold." Deal with the issues as they come up or they will fester and get worse.
See Each OtherFor goodness sake, make plans to see each other as often as you feasibly can. If you're two hours away, that might be every week or so. If you're thousands of miles away it may only be once or twice a year. There's nothing like being in the same room with the one you love, so make sure you put an effort into getting there.
Plan in advance who will travel where, how often you plan to see each other and how long the visits will be. Share the load. Don't make one person travel all the time, unless that is the way you BOTH want it.