Turning a guy friend into a boyfriend?

My best guy friend and I have been friends since we started college four years ago (we just graduated). most of the four years (all the but the first one) were spent at least 5 hours apart but we were very good about visiting and staying in touch. so far this summer we have been emailing a ton (no phone service in the country he's in), and they are very long and thoughtful messages. he is coming back in a month or so and we are going to visit each other. the thing is, i have, and always have had, feelings for him. i want to know how i can make my emails a little "sweeter" and get him to start seeing me as more than just a friend. we have kissed a couple times over the four years but nothing came of it. i don't know what to do but im wondering if there are some things i can say so that by the time we are together he will start thinking of me differently.