My rule of thumb - and I'm mainly sharing COVID stuff and dinosaur stuff, not stuff about Ukraine - is to look at the source.

There are known trusted sources that I trust about their relevant areas of knowledge
for example

ABC news Australia;

the Western Australian government;

the Premier of Western Australia;

Smithsonian Magazine;

major accredited museums (for museum news);

major accredited zoos (for animals/conservation news)

If it's not from a known trusted source, I check the profile to see if it lists credentials for the account holder.

For example, I see that a science-minded friend on Facebook has shared posts from Dr Mo Assoum about COVID

the posts seem science-based, reasonable, and measured - cautious and seeking to reduce risk, but not catastrophising - so let's look at his bio

BSc, MIPH(hon), DGIS, GCRS, PhD (Infectious Disease Epidemiology)

okay, his bio links to the official website of Mercy Global Health, Global Health and Development Specialists

and the website of Mercy Global Health lists him as Founder and Managing Director

Yes, I feel comfortable sharing this.