Here is the reference (from pixabay.com). I’ve chosen a picture with bold colors and no distracting background.
First the drawing. Simple but deliberate lines here – no sketchy lines. And only a little detail on the plumage just to identify where the colors change.
Once the drawing is done I loaded up the reference into gimp (free image manipulation software) and reduced the pictures to 4 grayscale values. This makes it easier to see where the lights and darks are. We can see that the top of the head and top of the wing are the lightest areas. We need to make sure we don’t over paint these in the later stages to keep this difference.
The first layer of color is put in quite broadly. It doesn’t have to be very even or neat at this stage. These colors will show through as the lightest color values in the finished picture.
At this stage the painting will look terrible as there are no contrasts between light and dark. This doesn’t matter – just push through.
After the previous layer has dried the next layer of color goes on. I’m leaving the previous layer to show through as the lights on the feathers at the back of the head and top of the wing. I strengthen up the color on the front of the head and chest and a darker blue on the front of the wing.
We’re starting to see some form appear in the head and wing but the painting still doesn’t look like much.
This is the final layer and even though the amount of paint applied is much smaller than the first two layers this is the one that makes all the difference.
Using a fairly thick mixture of ultramarine and burnt sienna I put in the bottom of the beak and the small beak tip. The pupil is put in with the same mixture. Using a very dry application of cadmium red and a small brush I mark in a series of broken lines around the eye. Be careful to break up these lines – it will draw the eye and look unnatural otherwise.
The hardest part is next. Putting in small areas of dark to indicate the feathers. Be careful not to overdo this. Only a few areas underneath each row of feathers need to be defined and then blended out on one side to show small areas of shadow.