Nature is a great source of sustenance, but one should remember a few common rules when foraging for Her gifts. First of all, never pick more than a third of whatever you’re acquiring for your needs, be it a crop of plants or a bush of berries. This way you can always return to a spot in the future and be sure there is more to pick. Secondly, be gentle! Don’t pull and rip, like some savage. Use a sharp knife and cut off only the parts that you really need.
And lastly, always clean whatever you gather. Use clean, tepid water. Plants might cure whatever ails you, but I guarantee they won’t be good for you if they're still covered with animal piss!