"How to accept a compliment. Thanks or agreement feels egotistical. Trying to act as humble by playing it down doesn't seem to be received well either."

I'm now in the habit of accepting and reflecting. Not only is it generous, it also tends to be true. "Wow, Bob, you got N done really fast and you did a great job, thanks!" "My pleasure, Steve - I couldn't have done it without Mary's help." Getting in the habit of forcing myself to give others credit _really_ opened my eyes to how solo efforts are still group efforts: "My pleasure, Steve - I couldn't have done it without Mary picking up my other clients' work during this project."

Worst case scenario, where you're convinced it really is solo work or where deflecting 'correctly' takes too much explanation, accept and deflect to the praiser. "My pleasure, Steve. Thanks for saying something."

I'm not sure this approach is "right", but it's what I've been doing in the face of the dilemma you mention.