Being remembered as fun is nice. Being remembered as the person who was safe to talk to is better.

Fun is easy to admire and easy to replace. Being safe to talk to is rarer, because it costs something: you have to keep what people tell you, resist turning it into a joke, and stay steady while somebody says a hard thing badly. People sort their friends quietly by this, and the sorting lasts for years.

Start by not repeating one thing you were told in confidence, even when repeating it would get a laugh. If a friend goes quiet this week, ask once and then wait. Being the person who waits is most of the job.