money

Are you technically skilled using whatever software you are trying to help? many FOSS projects need help with their documentation.

A few often overlooked ways to contribute:

• artistic contributions: logos, banners
• user interface design (I wish more UX folks participated in OSS, many projects could use the love)
• improving documentation: as a new and/or novice user, you're probably more sensitive to jargon that developers overlook and can help make documentation more useful to others like you
• accessibility testing: testing software using accessibility settings like high contrast color schemes and screen readers. these use cases are often overlooked
• project management: participate in the issues, see if the team wants help triaging or managing a discussion/chat platform

Even if not code, some of these are quite specialized. Just be realistic about where you can add something useful.

For all of these, it is critical that you first contact the maintainers and ask what they would find useful. Be mindful that it's also work for the maintainers to manage your help. The only "wrong" way to participate in open source is to drop a bunch of work on someone unprompted.

Generally, if a project already has a clear call for contributions or a contribution guide, that is a good indicator that the maintainers are willing to do a bit of community management to bring in help. I would only suggest investing energy in those projects if you have the choice.

You can also promote them in OSS focused forums many people might not know about those softwares and OSS doesn't have money to spend on ad campaigns.

Docs or QA. If you find bugs that you're able to test, it can be helpful to add a comment whether you were able to validate it or not. A lot of times basic information is missing, like screenshots, logs, and versions. This means step one for the maintainer is probing for more info

• Bug reports
• Sharing on forums, private groups, website like AlternativeTo, etc...
• Documentation
• Financial contribution even if small (Open Collective, Liberapay, Bitcoin, PayPal, Ko-Fi, Cryptocurrencies,...)
• Localization / Translation

You have found a niche maybe. Find a FOSS that needs french translation for it’s documents?

Helping test!!! We on the Jellyfin for Roku team have been begging peeps to help test code changes and releases before they are published for years. We get oh so little response, so it mostly ends up the two of us test each others changes on our 2 or 3 devices and if it works, it goes out.

We're begging for testers. I'm sure other projects are as well.