Ground: Try to keep earthworks minimal, but don't be afraid to move some dirt. Try to use the lay of the land as much as possible but if you want to raise lower a big green area or teebox, go for it.
Trees: since I placed all the trees by hand, they won't auto disappear. If you are trying to lay out a hole and some trees are making it unplayable, please MOVE the trees to a more convenient spot, rather than DELETE them.