I am installing a glass corner shower enclosure and plan to tile the walls. How high above the top of the enclosure should the tile be placed? I don't want it to go all the way to the ceiling. Also, how high should a decorative strip be on the tiled wall? Any advice would be appreciated.

84"-90" is normal for height.
Listello is typically eye level; around 60". But it's your shower so do what you think looks good.