We spend a lot of time teaching our kids to say Please and Thank You. It's a very admirable quality, at any age, to hear those polite and customary phrases. I do always wonder why, particularly in young girls, we don't teach the other side of Thank You, which is to graciously accept compliments, rather than to simply convey gratitude. We have no problem teaching them how to be meek and shyly dismiss praise, like that is some virtuous quality. It's humbleness... at its most anti-feminist.
We cannot control what others do. If someone wants to pay you a compliment, then they will. We can only control how we react to it, which is in one of two ways. Pleasant surprise and appreciation, which results in a Thank You. Super appropriate, always. Or, deflection, negativity, and/or a rebuttal. Which, I think is just plain rude.
There are definitely reasons, at times, why you might feel you are not worthy of such praise. And there are a lot of strategies we subconsciously employ to "correct" a situation that doesn't need correcting.
Do you assume the other person doesn't mean it? If you're willing to dismiss the compliment anyways, then does it really matter? You are not taking on any huge risk by believing something positive that someone says about you, unless you are narcissistic. I'm betting not, if your initial reaction is that the compliment giver is disingenuous.
Do you deflect? Oh no... you are much better at that than me. Followed by pointing out all of your own personal weaknesses. You're not proving anything to the other person by being down on yourself. You're not changing their mind. And, taking their compliment and turning it on them, incidentally, does not make them feel special. If you wish to compliment them, then accept theirs first and then make your own.
Do you feel you don't deserve it? It actually doesn't matter whether you think you deserve it or not, you're not paying the compliment to yourself. Don't insult the other person by dismissing their praise- you are essentially telling them how they should feel about you. And frankly, that's not your business!
Do you secretly want more? Sometimes we lightly reject the reassurances of others simply because we are seeking for their insistence that we are not just good, we are the epitome. Your ego might be working against you here. If you genuinely want additional feedback about the compliment, then graciously accept it, and ask questions that will allow more details to follow. But don't be obnoxious- fishing should not be your intention.
Practice saying Thank You to compliments. Even when you don't believe them. Especially when you don't believe them. That's when we need to be inspired by beliefs of others to build our self-esteem and turn our negative self-talk around.