While I enjoyed your tutorial, my pedantic ways wouldn't follow suit and I went more realistic, sorry 

I also started with the sky and Billabong (we don't call this a lake in Australia) using ultramarine for the sky, and a deeper cobalt for the water.

As I've lived in the outback most of my life and love our red dirt, I washed the whole background using Raw sienna instead of your yellow... Hope you don't mind You gave me the courage to try something new, thank you! 

PS. I added birds.