Photoshop CS Custom Brushes

My question is about the custom brush effects for photoshop cs. I am pretty new, though I have created some patterns that I would like to use as custom brushes. These are 16x16 patterns and I have managed to intergrate them into the list using define brush preset. However, when drawing, I have trouble achieving a consistent effect. I will use these brushes which will appear clear at other times, discolored at other times, blurry at other times and so forth. I was simply wondering how to achieve a more uniform look, so that the brush paints a 16x16 square that appears exactly like the one in the brush presets.

Can somebody tell me if this is possible, and if so, how would I be able to do something like this?

Any help at all would be greatly appreciated. Thank you! :P