I found at home a very old disk of Corel Painter Essential 3, so I installed it and tried to see how it works.
I spent a lot of time trying the different settings for brushes, and fighting against some bugs and mysteries of this program, which works in another way than Photoshop but is somehow similar to Artrage.
I tried to follow a tutorial of the wonderful Corrado Vanelli from the last issue of ImagineFX, but looks like my program version is so old that I couldn't find many of the described tools, ahah.
As practice, I did a quick portrait sketch in honor of the great scientist and Nobel laureate Rita Levi Montalcini, who passed away few days ago. The reference pic is a photo found in Google.