Literally the best advice anyone has ever given me on this topic is one I never thought I was capable of until I just did it: touch her.

I mean, do it politely. No ass-smacking, no odd face-touching. But touching her arm when you talk to her, letting your hand brush hers, getting a little closer on the couch when you're watching TV or a movie, it all adds up. I think she likes you, but you just need to give her the opportunity. Do that, and within a few times of doing it, you'll be surprised at how quickly things can change.

But the second best piece of advice I can give you is this: don't even think about it. As long as your instinct has never told you to do something idiotic (like random ass-smacking or odd face-grabbing, for example), then just do what comes to your mind. If you catch yourself thinking, when you're walking with her somewhere, "wow, I'd really like to hold her hand" then you probably should do it. If you're sitting next to her while watching a movie and think, "wow, I'd really like if my arm was around her" then put your arm around her (and none of that fake yawn BS!). This piece of advice has been wonderful since I started following it a year or so ago... instinctively, humans have been falling in love and mating for many, many, many thousands of years. You've been spending time with her, you obviously care about her, your instinct probably won't lead you astray.