It sounds like you're trying too hard! If you're working with aquarelles, just put a little water down for each section of the flower and dab the water with paint and let it flow. If you let the paint do what it "wants", it'll be great!
Hm must try it. It's true. I think I try just too much to control the paint. In the end it's not what aquarelles are about. Thanks for pointing it, it's valuable advice because people usually don't see the most important things.