The ball has to be tight enough to hold shape, but too tight will make the finish streaky and is a bit like spreading butter with a golf ball...
Put some of your finish in a jar that has an air tight lid. This stops the whole lot from drying out and going hard between applications.
Put in your applicator, most of this will soak up initially.
Keep it with some finish in the bottom, helps with the drying out thing....
If the applicator applies too much, wipe off again with a clean piece of cloth.
I have found that with things like ink, a bunched up cloth worked better for application, and the applicator spreads it around better.
Take from it what you will, hope it helps