More straightforward: The AWA (analytical writing assessment is relatively easier to do well on than the rest of the GMAT exam. As far as school applications are concerned, it's also far less important than your actual GMAT score. So get it right, but don't spend too much of your study time on it.
Structured approach: Stick to the customary five/six paragraph template, use SC rules to write correct prose, and employ Critical Reasoning approaches to build arguments. See these rules in the GMAT: Verbal section
What to avoid: Be careful to avoid any unsupported assertions, rhetorical questions, intemperate language and cliché - they will cost you. Keep your essays very simple and clear.
KISS: Keep It Simple, Stupid! Originality of content is far less important than structure and clarity of your writing. The task is: can you write a coherent and workmanlike briefing note in 30 minutes? Most applicants who have held down professional roles for a few years won't find this a problem.
Scheduling: Budget your time carefully:
- 5 minutes planning
- 20 minutes typing
- 5 minutes proof-reading (crucial!)