Give them signals that you like them if you want them to make a move. Don't just say or do nothing and expect them to just know when you like them. You really have to green light men before they approach you because not all men are good at handling rejection just as some women aren't.
The signals you sent server the purpose of letting guys know its ok to make a move.
This could be anything from smiling at them (not looking away awkwardly) to laughing at their jokes, or giving them lots of superfluous compliments.
The question is too simple. For example what kind of places do you come in contact with guys. Are you overweight? Do you generally make at least some effort in your appearance. Are you shy? What kind of hobbies do you have? How do you generally spend your spare time or weekends.
Smile at guys, generally talk to guys, if you find them responsive flirt.