1. Take any word.
2. Count the number of letters in it.
3. Subtract three.
4. Call the number you get X.
5. Whenever you write, try very hard to wait X sentences between multiple uses of the word you chose.
Do that for all words. (And don't replace a word once with its synonym to bypass the issue - by doing so you introduce confusion as well as repetition.)
Thus you will eliminate much repetitiveness from your writing, and also get most of the long boring bureaucratic words replaced with short vivid equivalents. In certain technical types of writing, there is no advantage to these changes. But in the "humanities", I think they do an incredible amount to make your writing clear and interesting.