Big words belong in the dictionary, nowhere else.

A few days ago, I was walking near an office building and I 
saw this sign on the lawn:

Experimental Turf Area
Please Avoid Pedestrian Traffic on Turf

Honestly, that's what the sign said.  My immediate reaction:  
KEEP OFF THE GRASS has worked quite well in getting that same 
message across, for many years.  So why say so much more?

Best selling novelist James Michener used basic language.  In 
his marvelous book about his life and writing career--The World 
Is My Home--he made one recommendation in two words: write 
simply.  He explained:  I try to follow the pattern of Ernest 
Hemingway, who achieved a striking style with short, familiar 
words.

A superlative scholar throughout his life, Michener acquired a 
large vocabulary--but I never had a desire to display it, he 
observed.  He continued: Good writing. . .consists of trying 
to use ordinary words to achieve extraordinary results.

On this point, Michener tells about Somerset Maugham, a revered 
novelist whose career ended as Michener's began.  Maugham said 
he started a notebook when he decided to become a writer.  He 
jotted down words with nice sounds--big, impressive words.  
Years later, he reviewed his list, and realized he had never 
used a single word from his collection.

To quote Michener again: No writer has to use all the words he 
does know.

James J. Kilpatrick, a syndicated columnist and respected 
writing instructor, agrees with Michener.  He asks: What is a 
fundamental principle of writing?  His answer: It is to convey 
a message.  Kilpatrick says the writer's art lies in stringing 
the right words together artfully.  By artfully, he means 
without showing off.

To assure simplicity, write your first draft of a
Memo
Letter
Article
Job description
Performance appraisal
Instruction sheet
Annual Report

or anything else.  Then spend as much time reviewing and editing 
as you did writing.  Mark through pretentious words and phrases. 
Look for the most common words people prefer.  Almost always, 
they're available.

Examples:

Instead of fortuitous, use lucky
Instead of halcyon, use carefree
Instead of prevarication, use lie
Instead of optimal, use ideal
Instead of feasible, use possible
Instead of peruse, use read
Instead of interrogate, use question
Instead of altercation, use argument
Instead of surrogate, use substitute

Your next steps:

When others use words that confuse or annoy you, jot those words 
down.  Then make sure you don't use them in your speaking or 
writing.  When you absolutely must include words and phrases from 
your professional jargon, accompany them with brief definitions.

Remember: Simple words work best, just like:

KEEP OFF THE GRASS