Regarding the ask about small brushes and “hairy” lines, what would your advice be for someone who has always had those kinds of hairy lines when sketching digitally or on paper and wants to stop that, besides using bigger brush sizes obviously? I’ve taken a lot of art classes and this is the first time I’ve seen mention of it being bad practice and explains why I so often dislike my rougher work.
In general, whether sketching analog (on paper) or digitally on a tablet, the idea is the same. People’s lines are usually “hairy” because they’re drawing with their fingers or wrist, like in writing. This means their range of motion is only limited to how much their wrist can move, creating smaller strokes/lines. Shifting to “draw with your elbow” gives you a greater range of motion.
Sycra Yasin has a neat video about traditional drawing techniques. In the first 2-3 minutes, he explains this in greater detail with visual aid:
To improve your line quality, you can try these practice/warm-ups. Lots of people forget that drawing, like any motion or exercise, needs a warm-up. Even just taking one minute to do this can help you draw smoother, more confident lines.
The philosophy behind this is that by warming up your hand and eyes to connect two dots, you can more easily connect your lines in your drawing, leaving less disconnect/hairy lines.
For digital art specifically, make sure your stabilizer is on to a setting that is comfortable for you. The higher the setting, the smoother the lines. However, there can be some lag/drag on the highest settings.
In addition: drawing in small dimensions can add to the frequency of hairy lines. Up’ing your resolution to at least 1000×1000 pixels should alleviate problems with hairy lines and low resolution. This is more of a technical matter however, and will not be the solution for an untrained hand. So keep practicing line confidence and eye-to-hand-cordination.