Don't be an idiot, when your team is losing, insulting them and calling them shìtty will just make them preform WORSE, believe it or not.

Encouraging your team to victory, will most likely lead to a victory. Wars are won not by telling your troops that they're a bunch of failures, but by telling them that they are strong and loyal, and can win the battle and the war as an extension.

Basically speaking, don't be an ässhole.

Speaking of not being ässholes, let's talk about the kinds of ässhole that exist here on War Thunder.

The spawncamper.
AKA Those ässholes that either fly or drive directly into your spawn, wait for you to spawn, then one-hit your äss before you can even fight back, these guys aren't just ässholes, they're püssies.

The killstealer.
It's all fine and dandy if you and someone else begin engaging someone at roughly the same time and you end up getting credit for the kill, but if you see someone actively engaging someone and they've been doing so for a while, working hard to earn their kill, it's a pretty ässhole move to swoop in and steal the credit for the kill that they would've gotten if the kill system wasn't so broken if they'd killed it themselves.

The tryhard
Blames his team for everything, while not even once thinking that he's the reason victory is so far for his team. Basically speaking; Lacks self analysis.

The Max-Tier
You know the kind of ässhole that joins in a custom battle with jets and max tier heavy tanks (Like the maus) and completely ruins the fun of the battle? That's this guy.