We begin by cutting a gallon plastic milk jug in half. The bottom half becomes the bowl we mix the dye in, the top half becomes a funnel for draining (we drain into a second bowl).
After mixing the dye in our new bowl, we add a large handful of shingles and mix them with our gloved hand until all of the wood it coated. Then we dump the whole mixture into our new funnel and let the dye drain into the second bowl. Moving the funnel between the two bowls, we continue to dye the rest of the 1,200+ shingles in the same manner. Luckily, the dye does not smell.
After all the shingles are dyed and drained we dump them onto a stack of newspapers and let them dry for 4-5 days. Which is forever. Also, we stir them around every once in-a-bit so they don't get stuck together as they dry.
Now, there is a table of shingles awaiting a roof. After the new year construction will begin in earnest.