As a Guy who mainly be-friends with females, You should just talk with them and if they say "I have a boyfriend" just leave them, Don't bother with those kind of Girls, They are nothing to you.
You should approach them casually and make sure not to act awkward, I learned that the hard way, Just act confident and make sure you look good, If you don't look good they will think that you're "Messy-Looking, a Sloth." So make sure that you dress well and look good, Also be yourself but not yourself Alexmo you suck. jk