Simply replace the unfilled areas such as "" and "[date]" with your information.
[Name/ Affectionate Nickname],
I wanted to slip this note in so that you would know how much I miss you as soon as you opened your [suitcase/briefcase/other]. I knew with our busy schedules we may not get to talk to one another right away. I wanted to make sure you knew I am always thinking of you.
Even as I write this, I can't help but miss you- and you haven't even left yet! It is hard to sleep at night without your tender kiss goodnight or your loving arms to hug me. You are so important to me. I never knew I could love someone as much as I love you.
So, have a very good trip and know that I will be counting the minutes until you return.
All my love,