Avoid complimenting certain physical features. The thing is, if you build up a girl’s feeling of worth in a particular feature, in most cases that feature is going to go away over time and she’ll end up feeling worthless because it’s gone. So avoid complimenting butt, legs, etc. Eyes and hands are a safer bet.
Complimenting on physical features works even better if you tie the compliment to her personality or actions. For example, tell her that her eyes are beautiful and that you love how her determination shines through her eyes when she’s working so hard.
Don’t sexually compliment girls you don’t know well. This is the biggest no-no when it comes to complimenting girls. You will obviously see girls you don’t know that you’re very attracted to, and you may think that paying them a compliment is just a nice thing to do, but if you don’t know the girl then a sexualized comment is just going to make you look like a creeperand take your chances down into the negatives.
For example, telling her she fills out that shirt nicely.
Sexualized compliments generally only work with girls you are dating or have another very close relationship with.
Don’t compliment her just to try and get something you want. She’ll know. Yes, she will. Give her more credit. You should compliment her because you mean it and you want to let her know how special she is to you. You should compliment her because you want her to be happy. You should absolutely not Compliment her because you want shallow physical contact.
Avoid insulting compliments. There are some compliments which you might perceive as being flattering but are actually insults. Before you give yourself a serious case of foot in mouth, consider what you’re wanting to say and how it could be taken out of context.
If there’s anything in your compliment about her losing weight, stop. This can easily be taken the wrong way. Instead, compliment her by telling her how healthy she looks, tell her that she’s just glowing, etc.
Don’t compare her to your sister or mother in any way, unless there is a circumstance where this would be a very good thing. Generally if you’re wanted to have a romantic relationship with her, it’s not.
Any comments that end in “today” (ex. “You look so nice today”). This implies that she does not look good on other days. Ouch.
Don’t use cookie-cutter compliments. Things like pick-up lines, lists of compliments you find online, and other cookie-cutter compliments won’t work...because they’re all about either another girl or any girl. She’ll notice if you’re complimenting something that could be said to anyone and know you’re just trying to get with her. Compliment her and you’re golden.