Use Bamboo skewer type of instruments from an asian store and whittle it down until it is about 5 times the size of japanese incense or twice the size of nag champa incense.
You need to wet the stick, I use spray water but you could also use drops of water. Put around 7-10 drops of water on there for each 3-5 dots that you are attempting to get. Must use the sharp little knife quite a bit scraping and scraping until after 2-3 minutes the Kambo will decide on it's own to form into perfect dots. It has an inteligence all it's own, you only need to be on auto pilot.
The amount is the size of your dot basically a little larger than a standard match stick.
You know the burn is sufficient if your able to peel the skin off and see clearly where you did the burn and removal of ALL DEAD SKIN. The biggest mistake people make is not to properly remove the burnt dead skin. Be thorough. Use fingernails first to remove, follow with a wet towel.
Pick off ALL THE DEAD LAYERS.