Communication is key. You don't need to go on and on about your day. Just a simple text or email like "I passed that restaurant we both like and thought of you. Can't wait until we can go again." Care packages are good to. If you can get a snack that isn't available where your loved one is and it doesn't need to be refrigerated, send that.
Email,Skype,Send each other letters,take pictures,communicate on the telephone,watch the same movie together and then take about later on on what u guys did and didnt like,talk to each other about the events,situations and the new stuff in ur life,send each other stuff. :)