I try not to tell my feelings until there is a sign of reciprocation, this is for the sake of the girl, it can be really awkward. If she's available you may find it more effective to create an intimate environment (like watch a movie alone with her) and then lean in for a kiss. If that's not possible for whatever reason you may need to just bite the bullet and be out with it and look for her response. Alternatively you may hint in that direction and see how she responds to your advances. Yes, she may say no, think hard of what you will do if she does.
Don't cry, don't regret and don't blame
Weak find the whip, willing find freedom
Towards the sun, carry your name
In warm hands you are given
Ask the wind for the way
Uncertainty's gone, your path will unravel
Accept all as it is and do not blame
God or the Devil
~Born to Live - Mavrik~