Simply replace the unfilled areas such as "" and "[date]" with your information.
I was so glad to hear from you. When I receive a [letter/call] from you, it is always makes me so happy. I know how hectic things are over there. I feel like the luckiest [girl/guy] in the world that you took time to [write/call] me.
Everything here is pretty much the same as always. Although, it just seems like something is missing without you. [Soldier's Acquaintance] asked about you. I told [him/her] that you were being as brave as ever and [he/she] said you were in [his/her] prayers. You are in all of our prayers, mine most of all.
Every night, before I go to sleep, I pray for you and I send you a big kiss. Everyday, at [time] I imagine that you are falling asleep, thinking of me. I swear I can almost feel you thinking about me, it is a warm, loving feeling. When I get that feeling, I just want to wrap it around me as if it were your arms reaching out to hold me. I love you and miss you. I am so proud of you and so proud to be your [description of significant other].
All my love,