Here is a good video explaining why you get a taper on one side of the cut when plasma cutting. Keep in mind this is an Australian company. Being from Australia I think the direction needed is reversed from the northern hemisphere so you would go opposite what they say in the video. Still, it gives a good explanation of why it makes a difference.
Another great video explaining the different types of dross and how to correct for them.
A summary of cut height and pierce height
Gasses
Cutting holes
Torch
Pierce Height
Lead ins
Consumables
CNC Stepper or server
The Arc
Trailing Arc
Basic principles
Cut Height
Cutting corners (CNC)
Bookmarks