Recently, ngd appears to have reduced some of the dmg dealt by warriors - but it is still possible to grind very fast. In fact, with a certain method, it's possible to grind without ever having to rest for hp or mana.
So, at the risk of Doing An Enio:
Step 1. Get a spear, put enough points in passives so you can easily 3 hit kill a mob with gutting and 2 normals.
Step 2. Continuously strafe to the side while facing a mob, when you are behind and to the side of a mob, enter combat stance while strafing, and do a normal hit. Here is a pic to show where you should be standing and in which direction you should be facing, just get the hang of how far 2.5m is.
Step 3. While strafing to the side, "chase" the mob in a circle by using your mouse to turn around (for better precision). With some practise you'll be able to hit the mob when it cannot hit you. Use the mouse to adjust the "sharpness" of your turning, so you can wait as little time as possible between hits and still avoid getting hit.
Step 4. With some practise, you should be able to consistently kill the mob quickly without getting hit. If you're on a scroll and need to kill faster, maybe get all dmg passives and max berserk for 2 hit kills, although it may consume a bit too much mana.
This method should be adaptable for use by knights as well, it'll just take more hits to kill a mob.
Disclaimer: If ngd nerfs this method, it wasn't my fault.