I'm not fussy about lather, but when I was trying to get that royal fluffy lovely lather I found that it's best to have as little water as possible. I shake my brush till none comes off when i shake it... start loading it with product until the top layer of your brush has a nice thick layer... than SMALL increments of water at a time. Like 3-4 drops - whip it - and continue adding water until pleased.

If you added to much water... you can either add some more product, or do what i do and just whip it a little longer. Unless you added a boatload :P

Good luck.