contribute with your time. depending on the project, you can write the code, design the assets, help with translation, or even triage issues on the bug tracker.

First of all. If you don't have the resources to contribute don't. If you need to spend your time on your financial situation or family or whatever, take care of yourself first.

But assuming you do have time then there are various ways that you can contribute.

1. Use the software.
2. Share the software. If you have friends, family or coworkers who could benefit from a particular piece of open source software let them know about it. If you have writing or video making skills you can also help by publishing guides and tutorials.
3. Support other users. Whether they are people you know IRL or people on the forms or issue tracker it is always good to help others.
4. Directly contribute to the project. This depends on the project, if they don't have documentation about how to contribute consider reaching out and asking. Let them know what skills you have and how much time you can offer. Frequently projects are looking for people to provide support to users, write documentation, triage bugs or other tasks. Reaching out also helps make sure that the work you are doing is useful and follows the project's conventions.
5. Specialized contributions. If you have specialized skills like programming, graphic design, UX expertise, speak multiple languages or anything else then the project can often find a use for you. Again, I recommend reaching out first to make sure that the work you do is desired and in the direction that the project wants to go. If you don't have these skills right now it is never too late to learn either. There are many online courses (many free) that can help you learn to program or do design.

Good question!

IMO a good way to help a FOSS maintainer is to actually use the software (esp pre-release) and report bugs instead of working around them. Besides helping the project quality, I'd find it very heart-warming to receive feedback from users; it means people out there are actually not only using the software but care enough for it to take their time, report bugs and test patches.

For people without IT background, I can recommend Mozilla common voice. They plan to release an advanced AI model for text-to-speech or speech-to-text conversion, e.g. for an offline, open source alternative to Amazon Echo, Siri etc.

To train the model they need at least 10000 hours of speech samples per language. So you can donate your voice by reading aloud small snippets, checking already recorded samples or making up new sentences.

https://commonvoice.mozilla.org/

@SeekPie Documentation or translation assistance is almost always a good way to help.

Actually, you can help by testing the software you use and file the bugs you find. Testing could include usability, UI, spelling, and trying to break it by putting various inputs into forms, etc.

In addition, telling people about it helps too. Maybe do blog or community posts, etc.

And thank you for wanting to help, you're a kind person!

Whatever skills you have are probably skills you could use to help.

If you can draw, see if a project you like needs help with artwork.

If you know multiple languages, see if they need help translating.

If you are good at breaking things, see if they need help testing.

If you are good at being social, see if you can help answer questions in their support channels.

If you don’t know what else to do, just share links all over the internet telling how good their project is.

Everyone can help in their own way. :)

I contribute by fixing spelling mistakes

I'm doing my part

All the answers given are already pretty good!

But I would like to add: take part in the community, discuss with other users, make it lives and show appreciations for the contributors (and maintainers) work. They're human, appreciation and kind words are an universal currency :)