This is the kind of thing it can lead onto and the sort of direction which you might find fun.
First of all, decide on perhaps a flower you like, and the colours you want to play with. Limit the size your going to work on - say A4 If you have a flower in front of you, or failing that, a photo, all the better, but avoid 'copying' it.
Work quickly so that the entire study remains wet in places, allowing the paint to escape into adjoining sections. Don't worry if it looks a bit wonky, or isn't exactly what you intended, and don't scrap it!
For this I used my Pyramid brush, but you an use any brush you have to experiment with.
I like to use the Golden Leaf brush to stipple the surface inviting colour to move into it. Its important that you use a big brush, that opened out so that the speckled sections are not too small. If you poke about with a small brush you can only work in a very small area so the rest of it is all drying as you are concentrating on your tiny bit. Try and look at the whole study, not just the tiny bit you are working on.
You can now see if this is likely to work or not. Never paint a random colour onto your work and 'hope' it will look good. Its fine if you know its going to work, but if in any doubt, do try this.
If there is an area your a bit disappointed in, you can camouflage it using textures either stippled on top, or stencilled. You may want to create more interest in an area or soften a section.
If you are using stencils or make, the number one tip I can give you is to remember that 'water is the enemy of the stencil' your paint needs to be used fairly dry, sponge or stipple it on.
Backgrounds seem to unnerve people so adding something really dramatic can be rather fun if not perhaps a little daunting. If you want to play safe, use the same colours as you have used within the painting already, or perhaps try to add something totally different especially if you plan to add more layers on top.
Anyway, I hope today's post inspires you to get your paints out and do some watercolour doodling of your own.