Indeed, I have no single style of forest, mountains, rivers or most terrain features in a map that I consistently do the same. I am always experimenting and trying out new ways to graphically depict every map I create. I have half a dozen different ways I might depict mountains for example.

Although I personally find the way forests are depicted in this map as somewhat underwhelming that is a design choice and not a value judgment - I've tried styles in the past that may have worked for a given map, but I may not have repeated the technique. This is very subjective and there is no 'best way' to depict any terrain feature. As long as the reader of the map understands what they are viewing, that is the most important aspect.