That's lovely. It has a very natural feeling to it and doesn't really look aquascaped so much as just a piece of nature. Very good job. It pleases my eye.
They can be from scratch or just from a certain point onward. They help as a way to record when you add a fish, what your water parameters are, when plants need pruned etc.
Even though the tank is already started the first post could simply be a list of plants, fish, and equipment.