How do you endorse/support a code project that you find helpful, be it established, emergent or fledgling?
I think there are some obvious answers, but hopefully there will be some novel suggestions too.
If you use an open source project or code, then consider making a donation, even if small. Lots of hard work went into maing the software we love. When you buy a pay-for product, you vote up or down with your dollar by making a purchase, which in turn supports the project. In open source, you can of course contribute back with code, but if you don't have time, financial donations to the project are a great incentive to the current team to keep building the software - because people love it enough to endorse it with cold hard cash (and that's often rare in the age of software piracy)!
It is really going to depend on what state the project is in. If this is code that is avaialble as a completed app that's offered as free to try/purchase to continue then I'll probably pay for the app if I think I'll use it.