I was working on a still life this evening and realized, once again, what wonderful painting tools I have attached to my hands. Oil paint seems made for finger painting. Fingers are great for smoothing paint, blending, creating certain kinds of textural effects, and shaping blobs of paint. Even very early oil painters used their fingers often (we know because art historians find lots of fingerprints in Renaissance paintings).
I tend to use my fingers mostly in the early stages of painting, when I’m working large and am not too worried about detail. Fingers are great for making sure that you don’t commit to hard edges too early. While working, I am continually smooshing with my fingers and wiping them clean on my t-shirt or a rag. Fingers are easier to clean than brushes, so there is less tendency to inadvertently contaminate one passage with a color from some other part of the painting.
Of course, it’s important not to get paint in your eyes or mouth. I am very careful not to touch my face or hair while painting. When I’m done, I wash my hands very thoroughly. That’s particularly important if you use potentially toxic pigments, but good practice no matter what.