The key is to practice deliberately. Understand what makes a good painting is very important. This allow you to focus on specific things to improve on! While painting as much as you can is important and can be helpful, you need to intentionally pay attention to a specific element when you paint each painting. Maybe you need to work on making clean washes, maybe you need to control your edges better, or maybe you need to paint better looking shapes, and so on.
There was a time I had to focusing on painting clean washes. So I pay special attention to the wetness and the timing of the wash. I made sure I finish the washes in the timely manner, and left it alone when I had to. After I was quite familiar with the process of clean wash, I moved on to painting good shapes. So I slow down when I paint figures, cars and trees. After I achieved my goal, the process start over with other goal in mind.
That's not to say you only practice the action itself. I am not asking you to start painting swatches repeatedly or paint 100 figures. Deliberate practice means you focus on achieving something when you paint. You still paint a picture from start to finish but with a specific goal. If your goal is to make clean washes, then don't worry about the shape of the car and figures. If your painting end up looking nice and clean but the car looks quirked, it is still a success. If you are focusing on getting the right value, then don't stress yourself about the color. Build your skill one step at a time and one on top of another!
This is one of the reason why watercolor workshop can be overwhelming. The instructors can give a wonderful painting demo, but the students are struggling with their own version of the same subject. The masters has years of practice and can do a clean wash without thinking. They already know how the final painting is going to look! They no longer need to think about the basic steps of paintings. And that's what happen when someone says "they make it look so easy." Because IT IS easy for them! However, you can do it too, you just need to focus on one thing at a time.
