These are simple techniques to improve your writing:

• avoid the word “that”
• remove the words “I think”
• avoid the words that end in “-ing”
• short sentences. short paragraphs
• shrink your opening sentence

[source] https://medium.com/an-idea-for-you/the-two-minutes-it-takes-to-read-this-will-improve-your-writing-forever-82a7d01441d1#.9vxa6y4aa