1. Avoid the verb ‘to be’ and all its forms (is, am …). – Grade 10 English Teacher, Mr. Shannon
2. Write something once, then cross out the unnecessary words. – Yves Faguy
3. Avoid the use of “I” because it is stylistically poor and it bad for the ego. – Good to Great
4. Use positive language (i.e. avoid no, can’t, won’t) because people prefer positive thinking. – Neuro-Linguistic Programming
5. Use sub-titles, chapter headings, etc. – Yves Faguy
6. Open and close paragraphs with short, positive statements.
7. Provide much more context than you think you need. People always underestimate how much context is in their own heads and communicating that context to the readers is critical to get your point across.
8. Alternate long and short sentences, use language in the same way you use notes in music.

Great book on the topic: Writing without Bullshit (for business writers)

This piece by Paul Graham outlines where essays came from and what they are really for: exploring an idea, not making an argument.Essay here.