for people without time:
I'm of the opinion that I'm most productive (from a global perspective), if I'm not focusing on a specific project, but picking up tasks as they come along. Eg while working on some project I might find a bug in a tool: In this case it's better to deal with the bug properly and then return to the original project than to work around the bug to finish the original project as fast as possible.
Since this style of work fits badly with corporate structures I reduced my hours at my day job as much as I can sustain financially. This way I have more time to do work as I see fit: Mostly on free software, open hardware, creative commons and similar stuff.
If you want to support me (obviously I'm not asking for support of any specific project) the most useful way is to contribute to the same projects as I do or even adopt the work model outlined above.
If you think you lack the skills: That's most probably not true. There is more to do than science, programming, engineering, writing and translating. Reporting any bugs, problems and fixable limitations you find is very helpful and often the only skill necessary is enough patience to find the right place to file the report. Also helping other people (be it in real life or some online channel) getting started, filing problem reports, etc. is not only helping them but also helping the projects involved and at the same time a great way to learn new stuff yourself.
If you feel you lack the time to help out: Money is helpful too. See the head of this page for details of how to support my work with money.