Hey. Im trying to get a grup on polygroups, edge loops, panel loops etc. I recall i have seen on some movie somewhere that you can enable masking mode where it will mask only the area of a single polygroup, not masking adjacent polygroups. Im searching trough all the freaking menus and i cant find it 
edit:
ok nvm, its in “brush -> auto masking” and strenght of mask by polygroups to 100 (as 100% i guess).
You can also select just the poly group you want to mask with the others hidden select mask all or drag a mask box over the whole poly group unhide all the poly groups now just that poly group is masked you can now also invert the mask to mask off all the other poly group and edit the unmasked poly group you first selected.
This way is much easier to mask certain parts than using the auto mask feature in the brush pallet sometimes.
You can also use the mask by features found in the Mask pallet in your tools menu to get different masks.