I’ve got some standing orders of 1 or 2 euros every month for bigger projects like grapheneos and kde. And for small apps that I actively use, I try to donate 5 or 10 euros now and then. It’s not much but I believe if everyone is doing their part we succeed in the long run
I live by rule “if everyone gave me 1 euro…” so I donate 1 euro/month to projects I use often (but I send actually 12/year to spare the devs some trx costs) and 1 euro/year to projects that I use sometimes (again I send 5 Eur/5 years actually). I use almost only open source and I haven’t yet paid everyone. I also recently made an open source application where I didn’t setup any donations channel, I simply like doing it… Maybe in the future if I have more work on it, but not now…