Do you cook something he like? Take a pic of you cooking naked. A black and white picture of lacy underwear around your ankles from the side with stockings on and heels ... not the rest of your legs. Put on some thigh high stockings with lace tops and show the hint of it. Sometimes being sexy when your apart is hitting at what he is missing. Or you could buy a sexy piece of lingerie and over the course of his time away ( eg 14 pics for 14 days) teasing him with parts of the outfit.