there are two ways. you can draw out the branches of a tree and add individual leaves in a spade shape adding a line down the middle, or you can draw most of the branches, and end them leading into a bunch of leaves which you can do by doing the general shape of the treetop, making the edges more random and jagged, creating the image of a bank of leaves providing that border. I do mine the second way because the first way can be very tedious.
Adding Gerald and a bunch of his friends on the hill helps to add variety, and is great at filling up empty spaces.
Ok..... so today I took a close look at all of my tracks and they looked like hella **** mate. Now i can understand why I didnt get a feature yet. NTBF, fluvidus, hippocampi every freaking track looked bad. Not a single track has a line connected. I never knew I was so bad. It is time to be more patient in detailing. I will be releasing (a) better track(s) if I have time.