Trust him and be faithful... I've been in a long distance relationship for a year and we have a great relationship it help a lot if you talk a lot I talk to him every night for about 5 hours and text all day when I really start to miss him I just think about how happy we were together last time and how happy I will be when I see him again
You could e-mail each other or call on a daily basis,
Also, get webcams. My bf and I are long distance and we talk onVideo Chat Rounds on Facebook every night. It certainly makes a big difference.