For this exploration let's follow the same progressions we use for realist work, that is, light to dark and general to specific. I'll suggest a step by step trajectory which you can follow or not, as you please. Read it through one time before we begin.
As a first step, let's generate some shapes.
Paint a piece of cheap paper with an overall middle value neutral wash, and another one with a dark wash of the same color. When the papers are dry, rip them into strips and patches.
Arrange the shapes on a piece of unpainted paper, leaving some white showing. Photograph the arrangements you like best.
Now select a palette comprising no more than three colors.
Wet a sheet of good watercolor paper. Using one of your torn paper designs as a rough guide, paint big, pale, soft-edged shapes. Leave some white.
Some variables to consider at this stage:
Do your first layer shapes touch each other? Do they touch the edges of the page? Are the sizes varied? Does one color dominate the design? There's a lot to think about
There is no "right way"to do this. With no external source to compare to your painting, it can be challenging. Have faith, and don't give up. There are always more opportunities to resuscitate a lifeless painting.
The paper may still be wet, or partially wet at this point. Before you begin applying middle values, decide what kind of edges you want. Rewet any areas where you want soft edges. A spray bottle can be very useful here.
The colors you get by combining the components of your limited palette can play a significant role as background for the more intense original colors.
Keep an eye on the first layer shapes as you apply the second layer. Let some of the earlier marks and shapes remain visible. Saving some of the white areas can be important at this stage. You can always cover them later if you choose.
The final layer often involves efforts to pull the painting together. Glazing adjacent shapes to give them something in common, for example, or adding a stroke that originates in one shape and ends in another. This is when the darks and the purest form of your initial palette are called upon to punctuate the ramblings of the earlier layers. Stop while you think you're still not finished.`