Treat pain points as debt
Dave Ramsey has this great method for paying off debt where you start with your highest interest loan, focus all of your extra income on that payment, and then once you’ve paid it off you snowball that payment into the minimum payment of your next highest interest debt.
I think you can do something similar for products and user experience. Let’s call it The Pain Snowball Method.
Start by taking inventory of all the customer pain that’s been reported over the past month. Prioritize it based on what causes pain the most often. Take the top three reported pain points and dedicate time every week to finding solutions. Fix one of them, and then roll that time into the remaining two pain points until all three are resolved. Do it again next month.
As your product grows, not every customer will use every feature. In order to continue adding value for those customers whose needs are met, dedicate time to fixing pain just as you do to adding features.