Hi Andy, sorry I'm late, finally catching up.Excellent job on the figures and I really like the tutorial,will definitely be going back for another look. Like you, I spend ages looking at the real pattern before starting the painting,however I usually begin with the trio of green patches and then try to work the brown around them, but very soon lose my way and end up with an approximation which just about works.So you've shamed me into trying harder next time. :)Regarding the rain marks, my own method is to mix burnt umber oil paint with dark green enamel for longer control but also that any lines which are too large can be quickly washed away with a little thinner. When I'm happy with a particular section , I give the area a light brush of thinner which tones down the starkness of the lines and blends them into the background.
Also, if you dont have it , check out the Osprey book on Modelling Fallschirmjager figures,superb guide.