I have been trying to process all the information I gathered from Calvin Liang's workshop.
Block in the big shapes, but do not close off the shapes by butting your colors directly against each other- at first. This gives you some leeway on the shapes.
Work from the foreground to the background.
Be careful when laying paint. Each layer should allow any under layers to shine through.
Architecture is tight at the top and loose at the bottom.
Shadows in trees are up high in the canopy, and the lower part (trunk) is lighter.
The bottom edges of everything should be soft.
Always test a color before laying it down.
I am still learning from that workshop. Money well spent!