It sounds like you just need more practice while paying more attention. Learning to do it without paying as much attention is something more instinctive that you're not likely to get right based on just reading answers here.
So I'd keep on doing what you're doing, but pay much closer attention, and stir.
- How does it look? Pay attention to the consistency of the liquid. When you free up open space in the pan, how does it flow into it? How does it stick to the solid vegetables/meat? How does it stick to the spoon/spatula, or flow off of it? All of this will change gradually as it reduces/thickens.
- How does it feel as you stir it? Be sure to scrape along the bottom of the pan some, especially toward the end. You can feel when things are starting to stick.
- How does it sound? There's a big difference between the sound of a large amount of mostly-water liquid boiling through the whole pan, and the sound of a small amount of thicker liquid boiling mostly just on the bottom.
- How does it smell? Especially if there's any sticking to the bottom, drying out, and cooking faster, it will smell different.
- How much steam is coming off the pan?
At some point, I would also definitely consider adding water incrementally as you cook, so that there's always a bit, but it also will only take a couple minutes to cook off. That also has the benefit of it always looking pretty similar to how you want it, so you get a lot of practice seeing what that looks like.
Finally, if you're trying to really dry it out, to the point where there's basically no water left, and you have a very thick sauce clinging to everything, then it's going to burn pretty easily. If you aim for that, you likely need to reduce the heat toward the end. If you have an electric stove, you may even want to just remove it from the heat.
If you do all of this enough, you should develop better instincts. You'll be able to glance quickly, or stir quickly, and gauge how far along it is. In some cases you might even be able to tell entirely by smell. (But don't rely on that! If you mess up and don't smell til it's already starting to burn, it's too late.)