Need advice on a relationship?

So I am in a long distance relationship right now. It is my fiancee and we are going to be apart for about another 4 months. I guess lately I feel like we have been drifting from each other a bit. I suppose I expected this to happen a little with the distance, but I feel like I am in a rut. So, have any of you been in a long distance relationship and what did you do to help avoid the drifting?