My play group has some problems with turns taking too long already, so I typically just say the spell name and, if necessary, as brief as possible a description of the effects. That said, I do usually come up with a general flavor of magic for each of my characters that comes up in less time-sensitive situations. I'm playing a summoner right now and all of his magic manifests as pulling things, creatures, or phenomena through to this plane from the First World. Prior to that I had a wizard whose spells all involved fireworks and moving tattoos. Ages ago I played an oracle who accessed all of his magic through ancestral chants.