Ever since I started doing digital drawings last year, I've used only a mouse.
I realize that there are other artists who have used a mouse or still use one, but they aren't as common as before. Most have moved on to using a stylus or even their fingers, which is perfectly normal in my view but that has never been an option for me. It requires a considerable amount of arm and hand strength, not to mention changing positions with the rest of the body. That of which I do not have the capability to do. That leaves me with a mouse. Using a mouse makes things more difficult for drawing and it's largly due to the fact that muscle memory doesn't come into play as much as say, when using a stylus. It's more about finding good techniques and the right brushes.
First thing I had to do was find the right mouse, one that I could have a good grip on for a few hours at a time. I tried a few different ones over the years and one that has stuck with me was the Razer Orochi. In addition to being the right size, it is a mouse designed for gamers and I could adjust the dpi (dots per inch) of the mouse or the sensitivity. When I started drawing with Photoshop, I also used a mouse stabilizer, of which I mentioned in a prior post. The stabilizer was just a simple program known as Silky Shark. I kept searching for an easier and better way to draw though.
After a while, I tried Illustrator to draw (especially since it has a built-in stabilizer) but it was better for doing lineart and then swapping to Photoshop for doing details (shading, coloring, etc). It didn't work out that well. I went on to try other programs and found one called Affinity Designer. It was a general drawing/editing software that could do most of what Photoshop did and had a very decent built-in stabilizer. I drew with Affinity for a while. I tried going back to Photoshop sometimes and after a while I got better at drawing with the mouse. As of recent, I can use Photoshop without a stabilizer, which gave me even more motivation to continue drawing. I swap between Photoshop and Affinity Designer depending on the project that I am working on.
Ever since, I've been on the search to find brushes that I could use to make things easier and have found 2 sets (on Artstation in fact). While they aren't all fully compatible with a mouse, some work just enough. Just recently did I find the second set (from Anthony Jones) and I'm still trying the brushes out. So far, I've found a few that work pretty well. In the future, I may just make my own but for now, I'm content on trying the ones I have till I get a better idea on what works with a mouse.
Just thought I'd share my experience and thoughts on drawing with a mouse as it was a big struggle for me. Maybe someone might find this useful or meaningful in some way. I find that the tools we work with are super important (which might seem obvious) and finding the right ones can take some time!