You do a little more than to your appearance than what you've been doing before.  Use a new perfume if you're a girl or a new cologne if you're a guy. Wear your favorite clothing item or accessory. Make sure it's something you've gotten compliments on. Start getting fitter and healthier. Exercise and eat more fruits and vegetables. This may seem obvious but many forget this. Remember that there is no pressure. You are just being friendly. Here are a few icebreakers to use:  Smile and make eye contact.   Compliment their wardrobe: "I really like your shirt." Make small talk about something relevant: "Are you going to homecoming?" or "Did our team win the game last night?" One of the best parts of having a crush is gossiping about it with your friends.  Sharing these feelings with them can make your relationship with them better. Also, your secret might reach other people and eventually get to your crush. Friends may try to embarrass you. Understand that this is part of the process. They will tease you even though they like someone secretly too. This might sound far fetched but you could become your crush's BFF (best friend forever). From afar, you may still wonder what this person is like. But as friends, you get to know your crush and they also get to know you. You could start by asking questions.  "What do you like to do on weekends?" "What is your family like?" "What do you want to do when you get older?"

Summary:
Take special care of your appearance. Say hello and be friendly. Tell your friends about your crush. Become friends with your crush if you're not already friends with them.