Also disabling your Anti Virus (if you're willing) will help, it eats up a LOT of system memory. And obviously closing all applications that aren't the game. Installing the game on a SSD if you have one.

Theres some way to allocate more ram to a game but I'm not sure if that works for server based games

You can overclock your cpu or gpu but you have to make sure they keep cool

That's all I can think of for now