Fey illumination will also buff Whispering Dawn. makes it quite usefull in large trash. illumination + rouse + dawn is an pretty strong Regen effect.

Emergency tactics + adlo is also a pretty massive heal especially under illumination and/or largesse. if you're lucky enough to see a crit can be an epic amount of hp on a tank.

the biggest tip though is use obey. and don't leave fairies in sic. selene you can kinda get away with as she'll just keep refreshing wind on cooldown. but eos theres not much worse than watching her pop dawn and illumination when your down to the last mob in a pack.

also if possible get used to placing your fairy and keeping tabs on it. may not seem terribly important but can make a massive difference.
fairys ignore a lot of battle effects and aoes so a placed fairy can continue to cast embrace on a tank while you might be legging it out of that telegraph or doing other mechanics hell even running laps of the arena and fairy will still embrace the tank.. a fairy on heal however will follow your every move and thus be unable to cast embrace if you are moving.