Write how you feel, there's nothing better than genuine feelings. Maybe write about what you miss about them, what you love about them. If you want to get really creative, you can do the list of the 100 things I love & miss about you. It's one thing to say you miss someone and another to explain all the things you miss about them & how you feel being away. Remind them of the reasons you love them and the affect they've had on your life. The best letter is a letter that comes from the heart so just focus on what you feel and write :-)
Well say how youu feel !! <3 always write cute things and how much you love spending time together ' also say that they mean alot to youu !!
What you thought of the first time you saw them. Assuming it was good of course!
Include an inside joke?