I put masking fluid with a masking pen, to protect the edges of the foreground. Let it dry thoroughly before starting to paint. The colors are DS hansa yellow medium, DS new gamboge, MG phthalo blue and S ruby red. Wet the background applying water evenly so that there are no puddles or dry spots. Float in the colors gently, the grey is made from a mix of the four colors. This layer has low values, the lowest being the area at the top left.
Let the first layer dry thoroughly, if you´re using a hair dryer, use it from a distance since its difficult to remove the masking if it gets heated. Wet the area again, this time with a spray bottle which has a gentle spray (a washed glass-reiniger/cleaner bottle works well for this) since a brush can disturb the first layer. Gently smooth out the spray with a brush if necessary. Lay in darker values using quick and confident strokes without going back and forth in the same area. Rock the paper to and fro to mix and blend the colors. Let dry thoroughly.
Mix some chinese white with the above colors (to make pale tints) to paint some background flowers and leaves. What freedom to be able to paint with white! Don´t forget to take into consideration that opaque colors dry darker when dry, unlike watercolors which dry lighter. I´ve left mine to finish after doing the main flowers, so it will be easier to see where to place them and how many.
Here´s my value sketch:
Watercolor Journal 