How do you handle not seeing your SO for a while?

I’m interested to know what you do, in order to keep your relationship going smoothly. My boyfriend and I usually see each other once a week, but in this past month I’ve only gotten to see him once- and he’s going away soon again, so things have been slightly more difficult lately. We don’t have petty fights, but I sure do get down not seeing him regularly, and he doesn’t express affection often which can lead to some misunderstood feelings.