How can I dye my hair as neat and precise as possible?

How do I make sure that the hair dye won’t stain my skin?

What happens if I wash out hair dye earlier than the instructions say?

What happens if I leave the hair dye in my hair longer than recommended?

What do I do when the hair dye got into my eye?

How do I make sure I don't get hair dye stains in the bathroom?

How do I use my extra activator?

My scalp is itchy. Is that normal?