After you put the dye on you can manipulate the dye with your hand or any other tool you may have. You can add water to help spread the dye or lighten the color. You may have to cover a misplaced spot as well (see below).
You can fold the fabric if you want that pleated dyed look. Just pleat it up, squeeze it a few times, then smooth it flat again. You can see the layer of fabric underneath protected by the plastic sheet.
If you find that you have a lot of dye puddling in your fabric, and you want to duplicate it, you can just layer another bit of fabric on top. It looks like this before you put plastic on and squeegee it.
Believe me, when the plastic goes on, and you rub it with the roller brush it looks exactly like the one underneath. See that green spot in the yellow? You can conceal that too!
When you place the plastic on top, simply manipulate the green up into the yellow to conceal your sloppiness!
Here is a shot of all the dye dripping down the backside of the dye table.
These techniques, and my style, isn't to aim for total accuracy in order to duplicate fabrics exactly. I like to just have fun with it, and now after a couple of years, I kind of know which colors I like and what textures I prefer. When I do solid colors I like the imperfections that occur. I also really like ombre and water colory looks. Another inspirational dyer on line is Melody Johnson at fibermania.com. She is the queen of beautiful watercolor-like dyed fabric. Check her out!