Painting a Jar of Water

Today I wanted to start with a subject that wasn't too complex.  So I chose a simple jar and filled it halfway with water and put it on a white ground and plain background.  To make things even more simple I decided to use just 3 colors: Titanium White, Ultramarine Blue, and Burnt Sienna.  With these three colors you can make a complete grayscale, and also go towards warm (sienna) or cool (blue).  It's a great place to start when you aren't yet familiar with color mixing.
My process here was pretty straightforward.  I started by toning my canvas panel with a light wash.  I like to start with a more middle value rather than straight white.  I visualize the composition of my subject on my panel, and then I start to sketch with thinned paint (in this case a mix of burnt sienna and ultramarine blue).  Then I start to put the paint on first looking at my subject in terms of light and dark areas, then slowly sculpting out the subject this way.  Since this particular subject didn't have a lot of very dark values, it was more of an exploration of subtle shifting middle tones.
I am pretty happy with what I ended up with.  I know it's not the most amazing painting, but I think it's a good start to this process.