It's pretty much just Sacred Soil, the WHM regen bubble, Astro thing, Doton, Shadowflare, Salted Earth, Leylines, and Flaming Arrow. Oh also Titan Egi puddle. You can stand in those (and should in the case of a few). Also a few boss-specific effects (Garuda EX comes to mind).

The healer bubbles are all big obvious bubbles. There's like maybe one unfriendly bubble I can think of in the game (Alexander Prime).
Doton is a brown puddle that looks like sand. It comes from a Ninja who is AOEing or screwed up their ninjutstu.
Shadowflare and Salted Earth are dark puddles that put up a big bubble that disappears during the startup animation. Summoner and Dark knight, respectively. Part of their rotations.
Flaming arrow is fiery ground. Bardz. Part of their rotation.
Leylines is a magic circle that appears where the black mage was standing. Part of their rotation.
Titan Egi is yellow barf on the ground that looks like what happens when you kill a Titan EX add. Used for trolling almost exclusively.

Everything else is a pwn zone.