Would you feel weird if this happened to you?

To make a long story short, yesterday in my Spanish cl we were playing a game with two teams in which we had to conjugate verbs in the past tense. A few weeks before yesterday, the girl I like had straightened her hair. I was going to give her a compliment, but I decided not to because I didn't want to scare off the girl and creep her out because a lot of girls get embarred when you tell them compliments in the middle of cl. Anyway, yesterday another guy complimented the girl I liked before I was about to compliment the girl about three second before I was about to say it. I decided that it wasn't best to say the same thing as him, because then the girl I like would just think I was copying the other guy. But deep down inside, I DID love her boots. Are there any other compliments I should give her, and is there anything I could have done differently the day that I liked her straighten her hair? The girl said thank you and laughed when the other guy gave her the compliment, and it sort of made me feel jealous because she laughed at some of my jokes before. Should I have given her compliments a week or a few weeks ago so she would've known I liked her? Also, is there anything I can do to show her that I like her. I'm looking for ideas of sincere compliments. Thanks.