This is something we have always looked for in hets and its always been fun chosing poss hets we believe will prove out.

Every Het Hypo we own or have produced has a spot on the head, not always a lighter overall look but this spot is always prominent in the middle of the head. We have also proved out poss. hets that we believed would prove by the head spot, have two more poss hets to go that look the same. Most het Caramels we have seen have alot of blushing and high golds, we picked a poss. het out of a group a while back by these marks and hope to prove her out this year. Het Pieds do seem to have melting patterns and seem to have darker patterns, train tracks appear on all of ours but we have seen proven adults without them so its just a common thing but not for sure. We have actually noticed that Het. Albinos seem to have a rougher skin and have a harder time shedding than normals and other morphs, not sure if this is always the case but it seems prominent within our hets. Now I would guess most of these are just line bred traits as all hets come from one or two original animals from Africa and are bred back together, so it will appear stronger in some animals, but none the less a sign. As for ringers in het pieds, I believe this is the same effect as a paradox and the gene is dominant in these skin cells allowing the pied to express itself within this small space. Its actually believed that Paradox animals are almost always Hets. and not the Homozygous form, as there was a Paradox Albino bred to a Homozygous Albino and hets were produced. Usually normal is a dominant allele to one Recessive allele but I believe in these cases in the areas of paradox the skin cells had a somewhat chimera effect when the skin cells were produced, but the overall genome of the animal was still a heterozygous recessive.
Long post but throwing out our experience with these markers and just letting out some loose thoughts.
Hope this is what you were looking for, its late and I may have screwed up somewhere with wording but hopefully you get the General idea.