When tracking the guitars make sure to eq out all of those pesky midrange frequencies that produce tone. That's very important when trying to make the guitars sound like a quacking duck inside of a wet cardboard box. You'll need to triple or quadruple track the drums in order to capture enough arrogance. Overplaying is also very important in capturing the Lars vibe. When trying to sing like Hetfield make sure to use plenty of throaty grunts and attach the sound "eeeah" at the end of every phrase whenever possible.