This picture is the best I think. I got the most vibrant color (see the corner) when I bound a smaller piece of fabric before soaking in the soda ash solution and then pouring dye on top.
Here is the result when I presoaked the fabric unbound and then scrunched it into a small container and poured dye on top. This piece of fabric and the last are bigger than the first. The color is choppier and there's an even amount of white and color.
And finally, this example is a larger piece of fabric that I scrunched into a small container dry and doused with dye. I poured in enough dye liquid to almost cover the fabric. After about 12 hours I poured a concentrated soda ash solution in with it. It's a lot dreamier, more of a wash and I'll probably use this for an under dye if I want something just a little more interesting than flat color.
The main thing that I'm still stumped on is the vibrancy issue. I may just not be using enough dye but there's a lot of colored water that I'm washing out when I rinse.