Battle for Azeroth’s War Mode puts you into PvP mode and grants you 10 percent extra experience. But since the two factions will mostly level in separate zones entirely, you should almost definitely have this on when you’re leveling. That said, if you start getting killed by random PvP players consistently, stop using it. Although 10 percent is nice, it’s not worth dying every few minutes for.

ConsolePort: A WoW addon which natively supports Xbox and DualShock controllers. WoWMapper: Third-party software for keyboard and mouse emulation. This software is not against the ToS, because it does not automate your gameplay. Multiboxers are without any issues using ISBoxer for instance. Xbox or a DualShock controller: Alternatively, you can use a Steam controller and enable Stream streaming. Setup instructions can be found here. DualShock's touchpad acts like a mouse, which is quite nice. A long HDMI cable: In case you decide to hook up your PC to a TV. Instructions
Heirlooms are special pieces of armor that level up with your character, so they have stats that are always respectable for your character’s level (up to level 110). Heirlooms that fit the head, shoulder, chest, legs, and back armor slot offer an experience bonus. The total bonus is 45 percent if you have them all. It’s also possible to acquire a ring that adds another 5 percent, but you must win a fishing contest acquire it, and that can take some time.