One way to increase your concentration and speed up your understanding of watercolor is to paint, in one sitting, from a fully saturated sheet of paper that, as it dries, produces increasingly harder edges.
Step one is to look carefully at your subject and think about the categories of edges, from most soft to most sharp. The more levels of soft to hard, the more interest and contrast will evolve, giving your painting more dimension than if you have only two or three levels of soft to hard edges. This kind of exercise, thinking about edges apart from subject matter and even color, will sharpen your artistic eye. It can be a struggle to see things in new ways, but once you do it a few times it will become a natural process. Along with your good observation skills of line, color and values, you will become more of a multi task painter, stopping less often to switch your thinking from one aspect to the other.
In addition, if you attempt this way of painting, you will have to plan more, something so many new watercolorists have trouble with. They hope to work things out as they go, and this usually ends up with a lot of errors. Once you are proficient, and quick in your decision-making, you will be able to make more decisions later, as you are working. But in the beginning, extensive analyzing of the subject, with those four ideas in mind (color, edges, values and line) will result it fresher, more spontaneous work than if you are stuck with a lot of repair work.
Also, painting in a very concentrated manner will help release your deeper levels of perception of what is going on with your materials. You are focusing on the drying paper, working with it to add and subtract water and paint, but in a more dynamic relationship than if you approach your painting in a wet a section, wait for it to dry, take a coffee break, then do another section. Taking your concentration away from the painting causes less awareness of the process.
It can be exciting working with “active” paper. Along with the water in the air, the water on the paper is alive and responding the actions of the painter. It feels more cooperative, and you begin to understand the nature of the paper in a new way.
To do this, soak a piece of 140 to 300 pound paper (remember, the thicker the paper, the more action) and place on a non-porous surface like Plexiglas. Have all your paints ready to be active as well, no hard lumps of paint allowed in this scenario! Fresh, or freshly active paint the consistency of toothpaste, and in large enough quantities (about a tablespoon each) to avoid breaks to fix the paint, will make the process go smoothly. You want to have nothing to worry about except the translation of your analyzing and the use of the materials. The more pre thinking you do to decide what you are about to do, the quicker the process goes: you can literally paint a great painting in one hour, with a fresher look than one you might slave over week after week.