@Malte I saw EuromaidanPress frequently organizing donation campaigns (even permanently, I would say). If you want to help Ukrainian refugees (at least in Romania) there is the dopomoha.ro website that gathers all the appropriate resources. There was also a FB group called Uniți pentru Ucraina (United for Ukraine) or something (it was written in 3 languages: Romanian, Ukrainian and English) where people would coordinate the efforts to help the refugees, find a place to live etc. Not sure how active still is today, as not too many people are coming anymore. Those who wanted to flee, already fled.
You can also do like me and buy music on Bandcamp from Ukrainian artists. Those that I know of are:
- Stoned Jesus (Stoner Rock)
- Vovk (Stoner Rock)
- Jinjer (Metal)
- Farba Kingdom (a post punk and darkwave duo from Ukraine, reestablished in Romania)
I am sure there are plenty of other bands.
If you also want something funny, you can also pay to have your name/message on a projectile fired against Russian forces. It can be a bit pricey though, but if you just want to send some money to Ukraine, just choose to enter any amount (you won't get a pic with your message though).
Also, if you want to contribute with something else than money, you can help DDOS various Russian websites using Disbalancer Liberator. Be aware of the risks involved, though.