I am working on keeping really crisp interesting white shapes, that move in and out of the other shapes. Notice how the white passage moves from the rocks to the house and into the background boats and water. This is a complex and interesting use of white paper. The foreground water is also a dynamic piece of white. When you are working transparently it is important that you really design your shapes before beginning to paint. If you just copy the photo than you will struggle with the concept of expressing the white shapes. Normally in real life the actual shapes are not seen as white and connected, this is a really complicated way to design paintings but really work the try. Take out a piece of paper and copy the white shapes to get a feel for them.
Use rich powerful colors to define the middle value shapes crisply cutting around the areas you have determined to be white paper. Keep it white don’t try to lift too much paint off of the white area, only lift as a last resort. I am using thalo yellow green, cadmium scarlet, alizirin crimson, hansa yellow, cobalt and cerulean blue and really trying to not overmix the colors. 
The shadows are cobalt blue, burnt sienna, and cobalt violet with some raw sienna for a warm reflected color.
With a knife scrape some highlights for poles, weeds and tree trunks.
Lots of white shapes–great challenge!
Nice art and good site-work too. 😉