So, I started to donate for science and education in Ukraine on a monthly basis, https://u24.gov.ua/
canceled Amazon Prime, switched to Ecosia as my browser and search engine, and left a (very minor) role in an advisory committee for a US government program.

(These are just some little steps, but you need to start somewhere)

UNITED24 — The initiative of the President of Ukraine

The official fundraising platform for collecting donations to support Ukraine

u24.gov.ua
Are there established charities that you would recommend?
@navatintarev.bsky.social There are Initiatives all through Germany, but I don’t have any anything specific. The link above is the government site. One has to hope it is used wisely, but I am willing to take a risk here.
(Perhaps the link got lost in the truncation to Bluesky )
@navatintarev.bsky.social That would be weird. Here it is https://u24.gov.ua
UNITED24 — The initiative of the President of Ukraine

The official fundraising platform for collecting donations to support Ukraine

u24.gov.ua