Can Someone help me understand these tiles? (references provided)

I recently have been creating sprites for world objects like trees...rocks....boats....etc but I have long since been plagued by creating worlds that are under detailed, flat, and weak in concept. I come here because these forums have been my main source of support and cause of growth up until now.

I am trying to build a world in the perspective of a Zelda game, but try to supply sufficiently more detail and bring the world to life while still keeping things simple.

I have looked far and wide for some inspiration...I liked aspects of Midora (such as the 32x32 tiles), and then some of artists I found on other sites(the worlds they created that had overgrowth tall trees...seasons...just simple changing to the environment)...For a long while I thought to get results I would have to dish out money for a contract artist to realize even conceptually similar looking stuff to what I wanted to have, but I decided that gaining the ability to realize the pieces myself is what I really wanted. My progress is currently show in my last post HERE

Though I'm proud of the things I've made thus far I have yet to even vaguely create any tiles to match.

I have been working on the concept of a better 2d game experience by allowing for 90 degree camera rotations which allows worlds to develop without the problem of vision obstruction:

This was an early test using Minish Cap tiles; I still want more refinement on the concept, but for now these simple goals suffice.

Now here are the references I have found and a few reasons I like them:

This one feels like there isn't a grid and the trees are shown to have broken in a natural manner or been cut into stumps


This piece by the same artist have a brilliant grasp on the perspective I am going for, and how it should show and conceal certain details in the world (this gives a great use for the camera rotation to allow the player to explore some more details)


This piece though incomplete I thing perfectly captures the feel of how I want my base world to look before it is given tall grass...rocks...cloud shadows....wear and tear....etc Joseph Silverman has been a huge inspiration for solidifying my choice style


This is the image I have boiled down to be my absolute ideal style...this would be awesome if I could actually figure out the steps to creating this style, and apply it to have the height and edges of a Legend of zelda game

I have some limitations to take into consideration that are very key to accomplishing the world I want
1. each material type (IE dirt, grass, water, sand, etc) must be independent of each other aka have their own spritesheets
2. each material should be able to be placed next to each other and create a readable edge (difficult but do-able through defining which material shows over the other)
3. some materials will be treated as an overlay exclusively and cannot exist on their own (grass goes over dirt....snow sits on the ground and is not the ground even if it covers a majority of it...etc)

I have thought through many concepts, that I know must be true for my outcome to be what I need it to be, but I need help in order to get started...I have seen many tutorials on tiling and spriting but none of them have come close to explaining this level of design and I find myself not making any progress no matter how many times I try. Please help me I look forward to your response, and I will post any and all progress I make here on this thread. 

I Do Not Own Any Images Above