Be limitless in the way that you approach your painting. We make the assumption that we have to use brushes when really the truth is that any implement, or even ourselves, can be used.
In the above painting, there were times when kitchen sponges, kitchen roll, the other end of the painting brush, a ruler and my fingers were used. The fingers are great when creating images containing texture. In this particular case, I used my fingers to add an extra softness into the clouds.