When you read the flavor text of a spell, have you had any strange images evoked in your mind?
For instance, when I think of Longstrider, I think of this:
For Longstrider and Expeditious Retreat, I want to get an app that plays "The Lone Ranger Theme". Especially for the latter spell.
One of the Dimension Door-type spells describes a disk that can only be seen from one side. Align both portals so they can be seen by me but not my enemy. Imagine his view back towards me, when my friends start charging through it. 
