Paying someone a compliment is a curious experiment. You mean well, and they're pleased, but somewhere in the middle it all goes wrong.
"That's a nice outfit," you start. "Oh, this? Well, it was the only thing that was clean this morning. I don't usually dress so smart. It was only £20 - it was reduced. I never go shopping. I used to go shopping loads before I put on weight but now it's such a nightmare. I never have time to do the ironing since Esme Grace was born . . ."
This then forces you to address some of the defences they've put up. "You haven't put on weight/Actually, you often look nice, but it was just today that I commented . . ." et cetera, et cetera. This then forces them even further into denying the compliment and before you know it, the sun has set and the last train has pulled out of the station. You meant well, and they will go home pleased, but far, far more words than you had anticipated have passed between you.
The more you receive compliments, of course, the easier it becomes just to say thank you. A friend of mine who must get at least ten a day responds thus: "Oh, thank you, darling, it's Martin Margiela," thereby in one deft sentence acknowledging both your words of kindness and giving you a bit of information, should you wish to "get the look", too (and also paying tribute to the designer). It is somehow less painful to take a compliment well if it's for accessories - shoes or a bag, for example - because these are not seen as being part of "you" in the way an item of clothing is, so it's like accepting a compliment on how cute your dog is.
Then again, nothing beats the self-assuredness of a French girl I once knew who simply shrugged and said, "Mais oui" whenever someone told her she looked lovely. Perversely, it didn't stop her getting compliments, as people became ever more elaborate in their procla mations in an attempt to get her to say something more effusive in response. Not a bad tactic.
It's actually tremendously ungracious to rebuff a compliment, because it doesn't make the person paying it feel very good if all you can do is come up with a list of excuses as to why you don't, actually, look that good, despite them thinking you do.
Telling a man he looks good is far more gratifying, because you can see him positively blossom under the attention (men don't generally pay other men compliments the way women do, for fear of seeming gay). But saying "You look nice" to a man isn't very helpful. You need to be much more specific: "That's a nice pair of shoes/ trousers" or "Nice shirt/belt" go down a treat. But I tend to give male fashion designers a wide berth these days, because I once made the mistake of saying to a very famous design guru that he looked great. "Of course I do," he snarled from his overly tanned face. "I'm a designer." That told me.