Here's a mini-lesson from Hofstra University's Professor Calitri. (I found it in the fall 2011 issue of neatoday.) Draw a figure on the white/chalkboard. Allow students to throw wadded up balls of masking tape at the figure. Next, students should describe where the projectiles landed. On the figure? Beneath the figure? Beside the figure?
Sounds fun, doesn't it?
This mini-lesson can lead to sentence revisions too. Sentences loaded with prepositions create a brain tangle for readers. This can be made obvious by diagramming said sentences on the board. In addition to "empty words" and unnecessary adverbs, hunting down masses of prepositions can be part of the revision process. This should be helpful for writers who continually use awkward phrasing and run on sentences.