Here are some primarily soft-edged paintings by Seattle artist Dodi Fredericks She is mostly working on a wet sheet of paper with relatively thick paint.
This one and the one below are entirely soft-edged. The paint stays where the artist put it , with just a touch of diffusion.
To give this a try, be sure to use 100% cotton paper, 140# or heavier. If you want to make a pencil sketch do that before you get the paper wet.
Soak the paper in the tub for 5 or 10 minutes. let it drip a bit before you lay it on your board. It should be uniformly shiny, so use a big brush to even out the wetness. Look for any air bubbles under the paper and smooth them out with the big brush. Depending on atmospheric conditions the paper will stay wet for at least 15 minutes.
The Paint you now apply can be a lot thicker than what you would use on dry paper. Because your paper is very wet you can think of it as your water supply. You are essentially adding water when you bring a relatively dry brush to the wet paper. There is no need to keep dipping the brush in the water bucket. Whenever possible, plan the progression of colors from light to dark so you can just add some pigment to your brush without adding more water. If you feel you have to have a little more water on your brush, be sparing. It doesn't take much to pick up some new pigment. f you need to clean your brush or switch to a new one, dry it a bit before you load it with paint. If it's too wet you'll get a bloom. You can usually test the wetness of the brush on a spot near the edge of the paper rather than right in the middle. Read this paragraph again.
You can use Dodi's paintings for inspiration, or work from one of the photos that follow.