Careful with the stinging nettle while picking and rinsing. It will literally "burn"your skin and fingers. (Its not harmful to the skin, in fact it is told to help the circulation, but it hurts!)
Pick all the above named herbs fresh and rinse any dirt off. Keep 1 liter of drinking Water to cook and add the fresh herbs (and sugar if you like). Let it cook for 10-15 minutes. You ll notice that the water starts to change color.