In dungeons, I will protect all and try to SS+adlo the tank at the start (and SS me/dps if the tank is waiting), then from there will only "pre-buff" on bosses. During trash pulls, if I have spare moments I'll SS the non-tanks (unless people are constantly losing it), and I try to time SS on the tank just as the last mob is near death, followed by an adlo as it dies/tank runs off. That way, everyone keeps a nice little cushion against damage, without needing anyone to wait on it. Depending on the size of pulls, I can usually throw in some dps this way.