Avoid jargon; use plain language.
Use standard written English.
Choose words with an appropriate level of formality.
Avoid sexist language.
Exercises:
Jargon, pretentious language, euphemisms, and doublespeak 1
Jargon, pretentious language, euphemisms, and doublespeak 2
Sexist language 1
Sexist language 2
Sexist language 3