It is not uncommon for me first to draw with a brush using gloss varnish to make marks on the canvas. This acts like a masking fluid that leaves the canvas exposed with white pattern when you drag the colour over the top.
Step One
I first start with a wash of pale colour washes using any medium (gloss) and water. I simply want to stain the surface and suggest marks that may appear to be flower like. I will then use a dark watercolour pencil to go into the negative space and find some