Tor: How can I support the Tor network without running an exit relay?

Short answer

You can run a non-exit relay, a bridge, or a Snowflake proxy, depending on your bandwidth and hosting conditions. Bridges especially help people where direct Tor access is blocked. You can also contribute money, documentation, translations, or testing. Start with the Tor Project's operator requirements so your contribution is reliable and does not disrupt your connection.

Sources

Tor Project: Relay requirements, Tor Project: Relay types.