It took me a while to understand the difference between watercolors and gouache. Watercolors are transparent while gouache is opaque. You can layer colors more easily using watercolors as your medium, but as in any medium you will need to be careful how much you do that.
I was afraid of watercolors and gouache. I have seen some of the work artists who work in these mediums create and WOW! Just WOW! Pretty amazing stuff. One that I felt I was not quite up to even trying.
It began as a way to continue to be creative and paint regularly while my studio was being revamped. (Originally built without insulation in Florida heat. Not too smart on my part!). Using watercolors and gouache not only allowed me the opportunity to complete a painting in less time; but I could go back and work on a painting with so much more ease. More importantly, I was not destroying anything close by with drops and drips of acrylic ink or paint.