Show up when you said, leave when you said, pay back what you said. Trust is mostly logistics.

Most of what people mean by character is schedule-keeping. Not deep honesty or grand sacrifice, just the unremarkable business of doing the thing you said at the time you said it. That is partly good news, because it means you do not have to be a better person this month to be a more trusted one. You have to be a more accurate one.

Make fewer commitments and make them exact. Instead of soon, say Thursday after practice. Instead of I will pay you back, say Friday when I get paid, and then set a reminder so the promise does not depend on your memory.