As a watercolor artist, I am a HUGE fan of softening lines. I know I've written about this before, but I think that softening lines to create a sun-dappled look is so appealing in a work of art.
After I finished this Autumnal Meander painting (below) and let it completely dry overnight, I simply used clean water on a brush to work at the edges of the hard lines in the trees ( I dabbed up the water with a tissue), softening up sunspots and lightening anywhere that I thought the sun might hit the branches and trunks.
It IS a little bit time consuming, but it is totally worth it in your final product. I am especially fond of softening up little circles whenever I paint foliage or florals. It gives the painting a kind of ethereal feel.
Happy Painting, my friends!