I think the most helpful tip I’ve had for watercolours is ‘to do it in two washes’. I wet the paper, then put on a wash of really bright tones, much brighter than what’s in front of me. If there are strong darks I lay those in too in the first wash. I let that dry, then, making my colour mixes much richer and darker; knowing how light they will dry, I add the rest of the painting in. Only things like boats and water will perhaps receive minimal work after that second wash.