Here's how I tackled the primroses the day before yesterday. I had a good reference photo which I had been lucky enough to capture a week or so ago when the sun was shining. I wasn't too impressed with the photo until I had a good look and saw the effect of the sun on the petals at the top. That was enough to get me inspired.
You have to wet the paper thoroughly before putting on the first wash and then let the quite strong, thick colours blend in the water on the surface of the paper. You have to have an idea in your head as to which colour is going to go where. I look at the ref. photo through half closed eyes to see the tones more clearly.