The biggest thing I can recommend is to take it slow until you learn his casts and can LOS them well. Wolf form = Safe mode, go ham, throw up immolate, let him path the full range if you want. Satyr Form = warning mode, will cast his dot on you so be careful not to allow him too much time to cast on you. Tree = Danger Zone, max range him at the end of his pathing and only allow him back in range to keep up instant dots.

If you have just recently jumped back on the ledge and are afraid of an inc cast run back along the ledge to the rock which will more quickly put him out of range and you can then jump off to LOS behind the pillar before hopping on the boulder and back onto the ledge. Don't lifetap while you have innervate on you you're just wasting hp.

Other than that just practice as painful as it is to die to a stupid mistake.