LAY SUMMARY
Read some articles:
Reputable pop science magazines (New Scientist, National Geographic)
News articles or lay summaries in research journals (Nature, PLoS)
Science articles in reputable newspapers or media websites
Reputable blogs – some academics / medical professionals run them, university PR pages
Topic
ENGAGE YOUR AUDIENCE
Pick an interesting topic
General overview of a drug? Major advance? Major adverse effect? Controversy / scandal?
Few references of key papers (minimum one). Non-experts don’t need exhaustive citations and won’t go on a literature search
Style
Scientifically accurate but accessible
Avoid unnecessary jargon and explain necessary jargon
Recognisable to experts and understandably to non-experts
Short sentences. Pizazz – sound enthusiastic, dramatic, literary flourish (but not too much).
Intrigue: pose a big question or big issue up front, make readers want to read more.
Most important facts first, minor detail last (newspapers)