As the maintainer of several popular open source projects (e.g. https://chezmoi.io), the forms of help I appreciate the most are:
* User support. Answering questions in discussions, social media, and GitHub issues. This helps on multiple levels: it saves me time that I would otherwise have to spend, and builds a community around the project.
* Documentation improvements. Better documentation means less user support work and helps everybody.
* Issue reports with a clear, minimal, way to reproduce the problem.
* Pull requests that follow the contributing guidelines of the project. This means that they follow the project's conventions, include tests, don't break any existing tests, and so on.
I don't write open source software to make money. I write open source software because I enjoy building high-quality software and I get a buzz from helping people.
* User support. Answering questions in discussions, social media, and GitHub issues. This helps on multiple levels: it saves me time that I would otherwise have to spend, and builds a community around the project.
* Documentation improvements. Better documentation means less user support work and helps everybody.
* Issue reports with a clear, minimal, way to reproduce the problem.
* Pull requests that follow the contributing guidelines of the project. This means that they follow the project's conventions, include tests, don't break any existing tests, and so on.
I don't write open source software to make money. I write open source software because I enjoy building high-quality software and I get a buzz from helping people.