Found something that I thought was missing, implemented it and made it open source ( http://chaiscript.com/ ). Now I consider it to be a rather significant part of my resume, having spent many years developing / maintaining / improving / supporting the same project.
As a project maintainer the things *I most need* from my users:
1. Tell me how you are using the tool! Very few people seem to be willing to share that information. It's huge. If I know how the average user is using the project, I know where to focus my efforts. Otherwise the squeakiest wheel is who gets my attention.
2. You tried my project and it didn't meet your needs, or the learning curve was too high? Tell me! I need to know where users are getting hung up so that I can improve and address those issues.
3. Submit bug reports. Specific bug reports. A complete compiling example is best, but any level of detail is necessary.
I've made a point of providing easy places ( http://discourse.chaiscript.co... https://github.com/ChaiScript/... ) for users to provide feedback.
Oh and:
4. Your favorite project is probably maintained by only 1 - 4 people. Understand that they cannot tailor the project to meet everyone's needs, or address everyone's issues. They have to prioritize their time. I'm in the fortunate situation to have a lot of time to work on my project today, but it could EASILY be a > full time job, and it's just a small scripting engine.
So, of the answers here the "participate in the community" is probably the most helpful to me, as a developer.
-Jason