Here is the view out my window and the resulting iPad drawing. After trying this many times, I have found that one has to build up layers - from general to specific, from light to dark, from background to foreground in order for this to work. Stay in one color circle until all the areas are blocked in. Then go over and add color - add detail - to create three dimensions.
step one - search Evyind Earle on the 'net and see what his work looks like. Step two take some pictures of the landscape that you can use - need to show layers. Here are two from nearby.
Next think about how you can stylize and Disney-fy your image and add other elements if you like. See below for examples.