how long will he be gone for? why not try mailing him something special that would remind him of u? but as one of the girls said.just tell him what ur thinking of now or tell him what you are doing to yourself from thinking of him.act out how you would masturbate with him on the phone.and tell him what you are doing and wearing? hope that helps.
Message me.I got you covered. I did this for another girl not too long ago as well. It's too long/graphic to post on here, so just send me a message and tell me what you're looking for and I'll send it right on over to ya.