dont be fake.

the very very very first of all is really important. DO NOT pretend to be someone you're not. don't try to change yourself for her. its really hard to actually change your personality, and what if she falls for you? that facade of yours will crack and break eventually, and knowing she fell for a stupid trick will crush her. and about 85% of the time shell warn her friends about you. or the entire school.
especially if the girl is considered 'popular'. then you'll find that you'll be exiled like you have a bad case of lice that not only itch, but will eat your face off.
do you like having a face?
i thought so.
when she asks you a question that you already know her thoughts on, don't change your answer to match hers.
ever seen the movie cloudy with a chance of meatballs? do you remember when Flint said he was allergic to peanuts to get Sam to like him?
do you remember when she found out, and she was like...."um....seriously?" yeah. its a similar reaction (depending on how serious the question is.) lying to her will only make her lose respect, interest, and trust, so don't do it. and we don't ask questions we don't wanna know the answer to. when we ask your favorite sport, we wanna know yours, not hear ours. being so similar creates tension and competition.
the only questions you have to be careful about are,
"do i look fat in this?"
"does my butt look big?"
"am i showing too much cleavage?"
"do i look slutty?"
etc, etc.
there are ways to answer these without lying. example,
her :"do i look fat in this?" you: "it accentuates your curves."
her: "does my butt look big?" you: "it looks good!"
her: "am i showing too much cleavage?" you: "just right for me. i wanna punch those other guys for staring, though."
her: "do i look slutty?" you: "you look like you aren't a prude, but you aren't a whore."
GUYS, this is only for more sensitive girls. if your chick can take the truth, give it to her! i myself wouldn't ask if my butt looks big unless i wanted to know. though i don't really care if my butt looks big.
there's another thing you have to look out for: the questions that aren't questions. examples would be,
"today, Melissa told me i looked like a whore in front of the entire gym class." now it doesn't sound like a question, but its more like a test of your listening. this time, DON'T be brutally honest. shed probably be kinda upset about this and looking for some comfort. if you two are close enough at the time, hug her and tell her she looks beautiful. tell her she is not a whore, and that 'Melissa' is completely crazy and probably just jealous because she couldn't get a boyfriend to save her life.
another example of this would be, "i think my ____ are/is too____" like... "i think my makeup is too overdone. i should wash it off...." this shows self doubt. (most of the time.) its not as obvious, but she probably needs a little boost of self confidence. so give her a compliment, it wont kill you! try, "no no. you're makeup brings out everything good about your face." but then take it a little bit farther to brighten her day. but not too far. acceptable: "and has anyone ever told you that you have the most beautiful eyes?" NOT acceptable " and you just look beautiful alllll the time, so don't even say that." this sounds fine on the outside, but when you look farther, it can say, "I'm just sucking up to you and i just wanna get in your pants. so i don't wanna hear your thoughts or feelings. ever."
yes, girls are complicated. EXTREMELY so.
but I'm not kidding here. this works. I'm giving you gold here. GOLD. are you gonna take it?