I have three rules that never fail me. Follow these rules and your life will be WAY easier.
Rule #1: If you think she likes you, she likes you. You heard me right. If you think the girl in question likes you she probably does! This rule has never failed me. Every time I THOUGHT a girl was into me she was.
Rule #2: If she's hanging out with you she likes you. If you ask a girl out and she meets you she likes you! That's all there is too it! Women aren't dumb. They don't spend time with a guy they don't like, unless you've known them forever. If you don't know the girl that well and she agrees to hang out with you she's totally into you!
Rule #3: If she's hanging out with you make a f*cking move! Look at rule #2. If she decides to hang out with you make a move on the first date. Don't wait, be bold! She's totally into you! Even if she denies you she will respect you more and you can try again later. Be bold!
These three rules are soooo simple yet so many guys never follow them. Follow them and your life will be WAY easier.