What do you all do to keep focus in a fractal?

[adormtil.1605]

Focus as you as a player. Like for siren reef or sunqua where you know one mistake there can kill you.  How do you manage to stay alive until you kill the boss. Is there like a cheese way to do it. This are the only fractals that I still did not manage to be at least decent at. 

[Linken.6345]

That one is quite easy to cheese with necromancers and epidemic

[marielleberto.3865]

Basically just do stuff over and over again and try different utility skills according to each boss. But I would say that having a knowledgeable and experienced group plays a huge role in fractals. There is a way to cheese siren's reef by approaching the ship from the other side and making sure the whole party stands in the sand patch right before the ramp attacking the boss from a distance. For sunqua, honestly, just know the mechanics very well and get an experienced group.