Even with practice, and even with the gift of delicious results, adding layers to a painting is so often difficult. It is not yet second nature to me, not yet a part of the adventure into which I jump with unfailing confidence and excitement.
For Pete's sake, look at what I do to myself. I take a piece of paper—for example, in this case, a card received from the hospice folks who cared for my mom and our family a year ago in October, cut it into a few pieces, and glue the pieces in place. All the while, I know I'm going to paint over the collage. I know it will become no more than an element of texture in the completed painting. Yet I go on to add pattern on the page in a carefully and happily matched color. No wonder I have trouble adding layers!