Hey @Paul Z, welcome to the world of digital painting! I think your study looks pretty good! It would need polishes and some more refinements on the edges for a further development, but, as a practice on value and on getting used to your digital tools, I consider it quite successful - especially because it lead you to figure out a better way to set up your brush. Your question have multiple possible answers - there are several ways to work with halftones, and different artists may have differences preferences. For me, personally, for example: if I’m just sketching, I use a textured brush with a bit of pressure sensitivity (but with Flow jitter on, not Opacity jitter) and rely on the eyedropper tool a lot to mix the colors in a very rough way; and if I’m working on something I want to be more polished, I usually prefer to begin with opaque colors (no pressure sensitivity at all) and use separate layers to design each value area independently with hard edges, no texture, as if I was painting with vector shapes - then I paint over on a separate layer to polish the edges (and that’s when I work in the gradations and textures). This method makes it look choppy in the beginning and costs me a lot of time to complete the painting, but I find it to be what provides me the most control and flexibility over the result. But, of course, there are other ways! One common technique I’ve seen other artists use is to have just the basic hard round brush with some Flow jitter set to the pressure sensitivity, and paint in a slightly similar way to watercolors: from light to dark, in several “passes” to slowly make it look more opaque and defined. The key is to study and do some research to see what’s possible, and then experiment a lot in order to find what works best for you preferences and style. Please remember to be patient with yourself, as face this study and exploration mindset as a kind of play and as something for the long run, as a constant search for artistic growth. Besides value and halftones, also be mindful of the importance of edges - as you move on with your painting studies, eventually seek to study that too. As @Grace Mounce suggested, I can’t recommend enough that you take some time to check out CtrlPaint: https://www.ctrlpaint.com/library It’s one of the best digital painting learning resources I’ve seen online, and a lot of the content is free. It helped me so very much when I was starting with digital painting - a lot the techniques I still use, I learned them from it. The free library is already filled with helpful tutorials. And if you have a few dollars to invest, their paid series are also super helpful (if you get interested, I’d recommend starting with the “Basic Photoshop rendering” series). Once you feel like you have a basic grip and want to face new challenges, you might also like to check out the digital painting courses at http://www.schoolism.com. Hope this helps! Please feel free to let me know if you have any questions. Happy studies!

I like Jan's suggestion to use the mixer brush to smooth the gradients. I've also heard of creating a new layer and using the color picker to sample tones and, with pressure sensitivity on, blending between two tonal areas. I'm bad at explaining this but I learned this technique from Matt Kohr of Ctrl+Paint, who demonstrates it nicely in this video (which you may already have seen before): https://www.ctrlpaint.com/videos/brush-technique-blending Disclaimer that I am new to digital art, but I have found Ctrl+Paint to be quite helpful! And may I say that I really like the tonal composition of this sketch :)

You could also use softer brushes. Like the round brush with 0 hardness. But you would still have to come back with a harder/smaller brush and fix the harder edges. Like with everything, they all have their uses:) You could also try using the mixer brush on top of that to smooth bout the gradients. Its a great drawing tho:)