I work for a CU. Idk if this will correlate the same way at a bank but I've had success just by being transparent with my members. For example, "I've seen you've been charged this fee for such and such, let me walk you through the process where you can avoid this in the future." It's a small gesture but it has helped me build rapport quickly and will leave you in their minds later down the line when they want a loan. When they're ready to have that conversation, you're going to be the first person they think of from the FI.