I agree with Krys, they are not hard to make. I think some of the inconsistencies folks are seeing is due to the wrong matchups producing wrong pigmentation on the shanks. Work with white skinned birds instead of black and you should get there fairly easy.
As Jody said recessive whites are not difficult to make. It is not really white skin which is the biggest issue. All Orpingtons, including blacks, ought to have white skin; the alternative being yellow skin. Sometimes problems tend to arise from lack of genes to inhibit melanin in the epidermis & dermis
Easiest white to make is on birds which are neither extended black nor birchen. However gold under the white is said to contribute to yellowing & using a silver bird makes a nicer, cleaner, whiter white.
The trouble Dawn is finding is that people have bred black based recessive whites to non black based recessive whites. Making a recessive white bird on black can give a nice clean white, without the yellowing, but other genes are necessary to keep the pigment from the shanks....These genes are not necessary & therefore not usually present in non black based birds. When one crosses the two types of white birds, the genes preventing the pigment from the shanks can be lost.
From what I've seen nicer brighter, whites are made on extended black with sex linked barring, silver & inhibitor of dermal melanin.
