When there's large predictable damage (quake stomp, acid rain, quills, lightning storm etc.) I'll use temporal shield once I've done the fights a few times since it just works so well.
Fights without large hits and when I'm doing new fights or if our healers are struggling to keep me up I'll use ice barrier.
Occasionally on a new fight if there's a lot of mechanics and I'm having a bad day I'll go for flameglow and IW just so I have less to think about.