I've got his nature drawing book. It's a great reference and very readable. John is very enthusiastic, which makes for a nice role model to get inspiration fr

I've got his nature drawing book. It's a great reference and very readable. John is very enthusiastic, which makes for a nice role model to get inspiration from. I would say his stuff is quite focused on nature drawing and you should supplement with fundamentals, colour theory, perspective etc to build skills, as John's guides centre around his approach/style and there are many other ways to get there.