In her recent article, Conserving the Canvas, Professor Ruth Anne Robbins makes the following recommendations aimed at reducing paper use in legal briefs. The recommendations are equally appropriate for improving the readability of legal briefs:

1. allow and encourage or even require double-sided printing;
2. move to 1.5 line spacing rather than double spacing; and
3. adopt court rules that limit documents by word counts while simultaneously eliminating font and font-size requirements.

Ruth Anne Robbins, Conserving the Canvas: Reducing the Environmental Footprint of Legal Briefs by Re-imagining Court Rules and Document Design Strategies, 7 J. ALWD 193, 194 (2010).

The full article is here.