If you can't say to the eye, then write a letter. Moreover, this method is suitable for those who are in separation. Of course, send the letter by mail is not necessary, it will be too long to go before', and will make you go through. Write and send an e-mail, in the age of high technology is a very suitable channel for communication. In the letter tell her how you feel. Should not be timid, but to be too pushy, too, should be in moderation. Don't forget that you're a girl and should always remain a mystery.
If it is not possible to send an email, write a text message. Mobile phones now are at all. Here too there are subtleties. Do not write banal poems taken from the Internet. Much already would say a simple phrase "I miss you". As you know, brevity is the soul of wit.
Tell him directly what you missed in the eye. At your next meeting. This method is good because you can follow his reaction. After his words he certainly does not expect to hear from you, you will see how they will act on it. Of course, you'll need a lot of courage to come and confess, but do not be afraid. Any person, especially a man, will be pleased to hear that it misses the girl.