Send your child off with plenty of stationery, stamps, and postcards. Pre-address envelopes and postcards so she can easily jot a note and drop it in the mail.
Start writing to your child before he leaves. That way, he'll have a letter waiting for him when he arrives.
Keep letters positive and encouraging. Now's not the time to break the news about Henry the hamster going to hamster heaven. On the flipside, don't detail how much fun you're having without her.
Don't be discouraged by short and/or infrequent letters. Your child is probably busy having fun. Ask simple questions about activities and daily life she can easily respond to and that make it easy for her to reply.
If you get a "homesick letter" — one that begs for immediate retrieval and details the hardships of camp life — be sympathetic in your reply and remember that in the days since the letter was written, your camper may have changed her mind completely. If you keep getting them, however, call the camp director to find out more.
Review the camp's rules about sending packages (many don't, for example, allow food), and send a care package full of puzzles, books, and other treats.
Record a message on a tape from the family back home that your child can listen to in those wish-I-was-home moments. Surprise him with a mix tape filled with "hidden" messages from the family and some of his favorite songs.