So she’ll respond better to “I think your essay was brilliant, you must have really worked on it” for example, than to “Your lips are sexy”. And she’ll love to hear “Your writing really inspired me”.
Speak clearly, concisely, use emotional language, and say it like you mean it: “You look absolutely stunning!”
But you must of course be genuine — so she knows your words are true, sees warmth in your smile and real appreciation in your eyes.
Your compliment will fail if it feels like it has an ulterior motive. So “Nice shoes, wanna go round to my place now?” will fall as flat as a pancake.
And don’t exaggerate: “This is the best meal I’ve ever eaten” sounds insincere, while “That was delicious!” works well.
Don’t go complimenting her when you’re in the doghouse. It won’t help at all. And avoid backhanded compliments that only sound nice until their real meaning hits.
So resist saying “You’ve lost so much weight!’ or “Nice nails, are they real?” And watch your tone of voice – you know how the meaning of a sentence changes depending on which word you emphasise…