if you really want to work with pied, its important to hatch or buy some visuals. the best pairings to produce more of them are visual to visual, and visual to 100% het.

het piebalds often have markers, so when you hatch some possible het pieds, sometimes you can identify and pick out the het pieds. so its less guesswork than with het albino or het axanthic.

keep in mind that butter/lesser pieds tend to be all white with black eyes. they are very nice, because the eyes are black and its a very clean and pure white. but you most likely wont see any of the piebald pattern.