I wrote an all encompassing report for a client who is crushing it. At the end of it, I had to ask for feedback on the services I am providing. I had to ask, "Hey, I know I'm not perfect, so I need to know how I can improve for you."
Granted, I am in the position that the results are good, so that eased my anxiety. However, even if you are in a bad results situation, you have to ask these questions, you have to seek being better.