Someone once pointed out to me I had a tendency to momentarily scowl when complimented and then pretend I hadn't heard it.

Made sense because compliments made me feel weird, even though I freely gave them out.

Since then I've trained myself to smile, make eye-contact and say "Thank you, I accept your compliment with confidence," before returning to the matter at hand.

Agreed, though it took me an embarrassingly long time to realize that, haha.