Find yourself always reaching for those little brushes? Getting all caught up in the fine little details of things? Set aside your little brushes and reach for your bigger brushes. This idea alone rattles the nerves of many of my students. With watercolor painting, the fewer strokes you use to accomplish something, the fewer strokes you use to fill in an area, the fresher the end result will be.
I've done a ton of paintings on a 1/4 sheet of watercolor paper using a 1 1/2 inch wash brush, a 3/4 inch one stroke brush and a number 8 round. To paint larger areas with fewer strokes you need bigger brushes. The larger brushes hold more paint and more water for more continuous swashes of color. You can still add in small touches of color with the corner of the flat brush or the tip of the round brush.
Go big, go bold, let those big brushes do the work for you.