For light nurgle, puss like skin, colour I use:
Undercoat: Skull white
Base: Nurgling Green
Shade: Agrax Earthshade
Drybrush: NUrgling Green
Drybrush Nurgling Green
Wounds done with a carronburg crimson wash then coated with gloss varnish
For rotten darker green skin i use:
Undercoat: Skull White
Base: Knarlock Green (old
GW paint range)
Wash: Agrax Earthshade
Drybrush: Iyaden Darksun (old
GW paint range)
Wash: Druchi violet applied in parts I want to make bruised
Drybrush: Screaming Skull
Wounds done with Scab Red (old paint range) then a druchii violet wash followed by gloss varnish.
I've had success with both of these methods and they are not too complex. Hope this helped