6 Answers

I wrote a humorous survey note on bright orange paper to my husband and included a pen.  It was hilarious.  It broke the ice and I had time to get over my shyness. 

First of all, be glad you are too shy to put someone on the spot by walking up and saying, "I fancy you".  What if the response was, "I don't fancy you". 
What do you know about this special person?  Likes, dislikes, classes (if in school), hobbies, volunteer work, faith, etc. etc. etc.
Having something to talk about, or something in common, is a good icebreaker.  Perhaps you could ask for help on a tough question in a class you share (NOT an easy question).  Just a friendly smile and some eye contact is a good start.
Whatever you do, don't go professing your love when you don't even have a friendship going. And, when you DO "fess up, do it in a casual way that doesn't put the person in an uncomfortable position.  
Good wishes for you. 

Sign every dance. When I was a kid we would have dances every friday night, All of the girls would have a dance card on the admission table and If you wanted to dance with someone, the boys would sign the girls dance card. Then the girls would take the boys to the dance floor one by one who signed their card for the dance that came up. So if you signed every dance card you would have to be careful not to sign up two girls for the same dance….it’s by the numbers and the only clue to the dance style coming up was letters by the numbers printed on the card…LD-line dance, TA-Tango, and so on. If a girl didn’t want to dance a particular dance she would put a line through it. This practice was common in my day but schools today may not be continuing such traditions. I liked it a lot because shyness was not a barrier to getting to know others socially.   

You got "expert" answers. Just follow their advice. I used to by shy too :) Good luck!

Send her/him a card with some flowers.  If she doesn't appreciate it, go to the next person.

With the opposite sex, it's a number's game, unfortunately.  You have to kiss a lot of frogs before you get to the prince or princess.

Like Nike says:  JUST DO IT!

Get over it & just do it... Life's too short...