I can't remember where I got this set of Photoshop brushes but they give quite good painterly effects that also come with canvas texture. I applause this guys who made these so well. Everything you see here is the result of these brushes.
It gets easy to paint in Photoshop because we can vary the brush sizes from really large to really small to just 1 pixel. In reality, there isn't such a function as we are limited by the number of brushes we have in our container. Most artists don't have a wide range of brush sizes, and most of the time, they paint with not more than 3 brushes or some could finish a painting with just one type of brush. We can get greedy when we paint in Photoshop, and spoilt with choices. By limiting the number of tools you would use, we could in fact emulate the effect of painting with traditional medium. I illustrated this point by painting the above by limiting my brush sizes and I would only use 2 brush sizes in fact, thus resulting in a less crisp finished digital look. But of course the brush tool set I was using help a lot too.