Place yourself at melee, and keep in mind a in dangerous situation, a blink is enough to go behind the boss or to go out of a puddle.
Go as far away from the other as you can (assuming healers, concentration aura and totem can reach you). Keep in mind: The less you will be in a dense location, the lesser your chances to see the boss turning in your direction to Slime Spray.
About the ooze flood appearance: you will see before they appear the center of the damaging AoE, use as many gcd as you can to be well positioned for the moment they actually pop. If you do it right you will never have to use your blink. (check the key locations which are at the border of the AoE). (For Fire Mages Only)