James Gurney is an artist who paints in watercolor and gouache (opaque watercolor) mostly plein air... meaning in the immediate place in the environment (as opposed to using photos).

He has many videos and DVDs on how to do it, explaining his style. He makes it look so easy.

https://www.youtube.com/watch?v=p_M_lZ1ev4M

This one is from a visit to a natural history museum. When I was younger I used to draw at the natural history museum when I had a chance, in Ann Arbor Michigan. I love that place.

This video explains how to use just a bare minimum amount of tools, to get a nice result.

This one is very nice, and short too. with an ooopppsss as he drops his palette and water. The little painting is very nice IMO.

https://www.youtube.com/watch?v=Acmswl4fxkk

Watercolor Warriors....
this is a short video showing how he fixed his spillage problem. Trying to paint with wasps, wind and other challenges. In the end the weather won.
https://www.youtube.com/watch?v=_lbOgHrPD70

Painting rainbows:
https://www.youtube.com/watch?v=jE7WWmYL91M
This shows his studio? High whimsy! This is a cute and funny video. Not long either.
p.s. I have that exact Te-Amo box...I keep charcoal pencils in mine. LOL