About 10 years ago, GW released it's first batch of premixed washes. Gone were the days of mixing 1 part Future Floor Wax to 9 parts water, and then mixing 1 to 4 of that with an ink to create a wash that would settle correctly.
Since then, there have been other techniques that were similar - Dipping models in Minwax Polyeurethane wood stain, then Army Painters dipping process.
However, this was intended to give an overall wash to the model, and once on there, it was a pain to bump that paint level. I like to use GW washes for a very basic tabletop level. It instantly shades the model, adding depth, and still leaves it where I can go back later and add highlights.
So, working with washes. In traditional painting techniques, it is always suggested to start from the inside, working out. However, with the Splash and Dash method, utilizing block painting, I do a more controlled wash. So we have to start with the large areas first.
Okay, so for this model, I primed the model in Vallejo USN Light Ghost Grey. I wanted a light undercoat, and the majority of the model will be grey. I applied all colors in blocks, starting with the GW Mephiston Red, then GW Leadbelcher, then VGC Beasty Brown. After this, I cleaned everything up.
Over this, I applied GW Argrax Earthshade. If you see on the model, there is a deep pool of the brown. Be sure to take a moist brush and pull this off. These pooling spots can take a long time to dry, and can leave a real patch to the model. Some pooling is going to be okay, but you don't want anything big.
Once the Earthshade is dry, I took PP Cygnar Blue Highligh, and blocked out the arms, and armor plate on the head. After this dried, I washed this with GW Drakenhoff Nightshade. Once dry, I applied GW Genestealer Purple. Neatness is key here. You do not want to wash over the areas hit with the Argrax. Cleanup on that would be a nightmare.
Once that was dry, I applied a wash over the purple with GW Druchii Violet. Let that dry, and then go and pick out small details, applying targeted wash as needed.
And the block and washes are done. If you wanted to take the model a bit higher, take the base colors and apply edge highlights as needed.
Here is the finished unit