Bunch of paint progress pics:
Like with my other models, I used Vallejo acrylics. I start with a base coat, trying to match the color of the figure - for this NECA Bob Ross figure I'm using as the base, I mix the Vallejo "flesh" tone with white and a bit of red. Then I add the various colorings of the face, like the stubble beard growth that appears as a grayish tone, the lips, and some variations in skin tone before adding the eyebrows and eyes.
The eyes start with a coat of white mixed with a little yellow, then brown tones for the irises, black for the pupils, and a little redness around the edges. At the end, I used clear gloss mod podge to give the eyes some shine.
I laid down a base of white for the hair, adding a gray wash, which I followed with a black wash because it needed to be darker. After that dried, I added more grays, and eventually dry brushed lighter tones where needed as well as additional low-lights.
I use small brushes, but I also use a pin for some of the detail work. It's good for painting small spots like the pupils. I also use it to scrape away paint to reveal a lower layer, which is good for detailing eyebrows and other hair.
I'm not sure if it's 100% done - I'll see how it looks in the light of day (the eyes might need adjusting). I also may go back add some more hair texture to the top of the head of 3D model, maybe maje some other tweaks if I see anything the bugs me too much, but I'm pleased with how it turned out. I'll be putting it up for sale soon.