Hey guys,

I just wanted to ask about any ways to make my servers a little more active. Right now I'm running two servers: A PvE one and a PvP one. Both vanilla. But my communities are quite weak still so I was wondering if there's a way to promote them a little. Maybe some kind of forum of something like that.

Thanks

You have to come up with a unique concept that will make you stand out from the crowd!
And put your server on Rust Vote pages. 

Rust devs can blacklist your server for many things now days.
I even saw 1 comment where rust devs admitted to blacklisting servers whom use god mode too much.

It's absolutely insane they can and are actively doing this.
Sad truth is if you arent a streamer with tons of viewers or someone they feel they "like" , they could blacklist your entire community for something small and you wouldnt even know it.

Well, they're definetly not blacklisted. I can still find them in the community tab and I do get some new players - but not many...
I thought about modding my servers but at the same time I want to keep them as vanilla as possible. I would probably use mostly mods to improve the quality of life and not trying to make a "whole new game" out of it.

Are there some plugins wich are commonly popular that many players like to see on servers?

Try to be unique and have cool plugins but not like people do buy every paid plugin and add a lot of shit only to be "premium"...  When something from umod works you do not need to flex with something that's same but paid lol unless have something special in it. That means a lot of servers with basic plugins form umod also have success. I think most of the time cool stuff like Taxi/BountySystem/ and other stuff that I have as side features are great addition and players love them. But still no guarantee you can have pop...

Ex. In January when rust went popular with twitch drops, from my country 2 streamers played the game and yeah my server is the only one in the country but still without doing anything they entered in my server and got 60/69 full month... One streamer girl only walked around 2h and tried to eat the skinned rock with sandwich skin, died multiple times and left the game but still viewers, population and good... Later they stopped playing and again low pop  :(

Well firstly...Streamers are NOT helpful to server pops, they're a disease.
Honestly considered not allowing it on the server.
Youll get inflated with nothing but idiodic sheep following someone like a dog with their tail between their legs.
Think youre doing good, then poof the pop is gone because the sheep have followed the wolf.
You get zero insight into how your server is actually doing while they're infesting your pop. 
I cant say a good way to get your pop up, and voting sites are mostly scammy. But I can definitely say that streamers joining is more cause for harm than helpful lol.