Using wet-in-wet and wet-on-dry to paint elephants; I chose to use opaque colours to help create solidity to the shapes.
I used Indian yellow and Cobalt blue - both are opaque colours.
The smaller elephant was painted using wet-in-wet, the larger elephant was painted using wet-on-dry technique.
Firstly, I painted Indian yellow in a loose wash to create the overall shape of the elephant followed by Cobalt blue in a more dense consistency to create the shadows and help define the shape of the young elephant. When you have painted a wash which has quite a lot of water included you need to reduce the next wash to a much more dense consistency to ensure that it doesn't bloom and explode into the existing wash. You may wish to wait until the initial wash looks less shiny before you add the Cobalt blue.
The second and larger elephant was painted using wet-on-dry technique - I started by lightly sketching the elephant to give me an outline in which to work; I then painted Indian yellow carefully, leaving a few white/dry areas to help create the shape of the elephant. I waited until the yellow was completely dry before I added Cobalt blue to define the darker areas and the shape.
Each technique has it's benefit but I prefer to use wet-in-wet to allow the paint to merge and develop on the paper.
Hope you have a go and enjoy the exercise - let me know how you get on. Happy Painting.