OnePlus6

Root

Easy way

Use Tool All in One

Root with commands and some useful commands

Rom

Tested :

xxx No Limits (https://forum.xda-developers.com/oneplus-6/development/rom-xxx-nolimits-1-0-speed-ram-optimized-t3799167)

Best tested : xxx No Limits

Kernel

Tested :

Flash Kernel (https://forum.xda-developers.com/oneplus-6/development/op6-flash-kernel-1-00-t3801652)

Best : Flash Kernel

Links