Hi,
Im trying to create a UV map for my sculpt and no matter which way i paint the attract and protect layers to it, it just wont give me a clean map, the seams appear to just not change or just place themselves awkwardly no matter what i do. any advice and tips would be super great! 
been doing this all evening, iām at my wits end!
polygroup where you want the seams then enable polygroup in uv master.
it should force it to have the seams where its polygrouped
That appears to help, still abit messy, but I think i can play and make it work, cheers!
One way to get pixel-precise polygroups is by going into ZModeler and selecting the polys. Then like informerman said, UV Master will do the rest.
Yup I do the same way by polygrouping where i want the seams to be.
Other way you can do it is by going to a 3d program, cut where you want the seam to be, import it back into zbrush and then unwrap it. That way if you dont want individual shells of polygroups, you can have absolute control of where your seams will be.