I follow a few rules, some of which others have mentioned.
I follow about 15-20 people and organizations who clearly know their shit because of their background (journalists covering Russia for years, generals, defense industry writers, think tanks, etc.) and I watch who they reference/retweet/etc. When this started in February, I was following about 60 people, but over time, I found about 15-20 people who were putting out a lot of good content/data or commentary that covered about 90% of what was happening, and never missed a major event. These 15-20 people and groups I follow, were all pretty much predicting Russia would invade, and they had all been writing and commenting about Russia and/or Ukraine for years. They aren't journalists that hopped on an airplane and became experts within hours of making it to Kyiv.
OSINT folks are amazing. Many of them will happily self-correct and/or they will correct others making mistakes (they can be anal-retentive). And if you are a part of that community and you start showing bias (even for Ukraine), you will get called out, and they will dogpile on you for it. Some of these people have been into this stuff for years (many of them write for various defense industry journals, blogs, etc., as well as more than a few book authors). It actually feels like this is sort of their finest hour - all of the tools (software, satellite imagery access, on-the-ground reporting, geolocation, etc.) and circumstances (they have sources on the ground able to provide quick updates, Ukraine is a democracy and not trying to censor much, if anything (outside of OPSEC stuff), and a shitload of civilians and soldiers in Ukraine have smartphones and are willing to share photos and video) came together for them to truly shine and sort through and present a tremendous amount of data, whether it's extremely intricate maps or massive spreadsheets of dead Russian soldiers picked up from Russian social media or massive spreadsheets of destroyed or captured vehicles, complete with photos for each.
As mentioned, if Russia denies it, it's probably true
Ukrainian Government is not always accurate, but they are accurate more often than not. Their numbers about Russian tanks/personnel/etc. destroyed and captured, when compared to the OSINT folks, are turning out to be a lot closer to the truth than a lot of people originally suspected. And Russia acts like you would think they would act if the Ukrainian Government's numbers are accurate. While it's possible the Ukrainian Government has duplicate counts in the stats it releases (especially if multiple units are involved), they will also have the most accurate records of what's actually going down simply because it's the people doing the fighting and reporting their results up the chain.
The more angry and the more pseudo-nihilistic Russian TV commentators get about a weapons system or a country, the better it's probably performing, or the country is aiding Ukraine, in reality. And when some of them are losing their shit and talking about letting the nukes fly, there's a good chance that major shit went down over the past 24 hours, and it's not hard to figure out what pissed them off.
Kyiv Independent has been an amazing news organization. They will self-correct when they make mistakes, and they will even poke holes in things that seem to be really good - they were one of the first media organizations to raise the flag over the comments about the US sending the super-long range HIMARS ammo possibly being falsified.
BBC, Reuters, and AP are all usually very good, thanks to having reporters/freelancers on the ground.
Most of the "mainstream" media, especially in the US, are running stories written by people who are a few degrees separated from what's happening on the ground. This isn't necessarily bad, as they are trying to report on what's going on and they can reach a far larger audience, but they just don't usually have the infrastructure in place and on the ground in Ukraine. There's also been a problem of some of their high-profile reporters/writers being embarrassed at how bad they misjudged last February (versus the OSINT writers), and either they've been trying to make up for it ever since, or they are slanting their coverage in favor of Russia just in case Russia pulls it off and they can say "see, we told you Russia would win!"
Some caveats:
The Russian government heavily censors Russians social media these days. It's a wonder any info about deaths gets out. And we know Russians have cremated their own soldiers, so there is a fog of war when it comes to Russian casualties at times, and I think they are way underestimated.
The Ukrainian Government is not above releasing false or semi-false information for OPSEC purposes and/or to fuck with the Russians. They will also force soldiers and people in certain areas to stay offline (not posting to FB/twitter/etc.) if shit is going down, which leads to lulls in information gathering for the OSINT folks.
There are folks who present themselves as OSINT types, when in fact they are just war porn types, or people trying to boost their twitter profiles by latching on to current events and trends, including the "HEY LOOK AT ME I'M REPOSTING SHIT FROM OTHER TWITTER ACCOUNTS AND ACTING LIKE I CAME UP WITH THAT" types.
There are people in the OSINT community who have supported or done sketchy shit in the past (like Trent Telenko and his election conspiracy nonsense) and it's hard to trust them, because if they buy into some bizarre conspiracy, what else do they buy into?
There is stuff released (like audio of Russian phone calls) that sometimes seem very suspect, but ultimately there isn't anything proving many of them wrong, and more often than not, there is evidence of what the calls were about. It's just hard to know sometimes if Ukrainians learn of an awful incident and then generate a phone call about it, and you can't blame them, since it's just another tool in the modern warfare arsenal and Russia is the master of information warfare. FWIW, I've run some of them by a Russian friend, and he said they were definitely native Russian speakers, but that's not to say that it wasn't Russians aiding Ukrainians.
We don't see as many videos/photos from the Russian side of things, and it's hard to know if that's Russian commanders making sure Russian soldiers aren't putting out things that could lead the Ukrainians to pinpoint units/positions, or if it's a lack of internet or smartphones. And a shitload of OSINT folks are constantly trawling Russian social media looking for this stuff.
Russia clearly has a lot of bots and supporters on social media, and certain events will trigger them like nobody's business, like somebody put out the Bat Signal for them. That leads to a lot of stuff trending when it shouldn't, and other stuff getting buried.
I'm missing some things, but it's late.