When you start a painting, how often are you using a white canvas? This video offers an alternative. There are a number of reasons for using a toned canvas, though the easiest explanation is time savings. If you're looking to create a rendered image featuring a full value scale, you might as well start in the middle. In the video I use a warm tan color, though it's worth noting that gray works just as well.
If I was only allowed to talk about one topic to a beginner digital painter, this would be it. Form, value, and light are truly the foundation of a painting education. If you want to know more about making your own custom brushes from scratch, make sure to check out the premium seriesBasic Photoshop Rendering.
In art school, drawing 1 teaches you the basics of form, light, and shadow. This premium series approaches this fundamental subject-matter with Photoshop as the medium. Honestly, this is the foundation of painting, and if I could only recommend a single series from the store this would be it.
In the vocabulary of painting "value" refers to illumination. Light areas are high in value, dark areas are low in value. This video explores value sketching - in which a painter foregoes the line-drawing phase and skips straight to tone. If you've never done this sort of sketching before, it's a fantastic exercise!
From my experience, beginners are often taught to think in terms of line because pencils are so cheap and accessable. Working in value requires an artist to more carefully consider form and mass, which is a valuable way to think. Normally sketching in this way would require messy paints or charcoal, but working digitally makes using tone and value just as easy as lines.
Light and shadow reveal the form of an object. The way to create a likeness lies in the accurate depiction of shadows cast across form. So what should you look out for when painting light and shadow? This video explores shadows' tendency to have both hard and soft edges.
Note: It's not clearly mentioned in the video, but this technique is only relevant in the case of strong directional lighting. If you were looking at an object on a cloudy day, this principle would not apply.
Finally, if you want to know more about this topic you will enjoy the premium series available in the store: Basic Photoshop Rendering.