It should be a matter of working out the right ratio of water to soap.

I give one flick to the brush after the water stops draining out and I scoop out cream with my pinkie.

I try to be very consistent with the water flick and the size of the dollop of cream - once in awhile, I have to add a few drops of water, but my results are very consistent.

Just work up a recipe/technique that works and stick to it