I've created a magic effect similar to the Ice form shout, that is supposed to freeze an enemy on death, but I can't get the effect to persist after death. Anyone know how I could get this to work?

Pretty sure you need to use shaders to create an effect that will persist. Here's a http://www.gamesas.com/topic/1364122-pretty-sure-this-is-impossible-but/ hat I have been meaning to go back to for some experimenting. There are probably some examples out by now too.