Make it a habit, not an event.
Run the analysis at the second draft stage, after the ideas exist but before polishing, since that's when swapping a crutch word costs nothing. Keep a personal watchlist of your known offenders and scan the table for them first; most writers have fewer than ten. And when a word's count surprises you, check where the instances cluster, because eight uses spread over 2,000 words is fine while eight in one section is a problem.
The Word Frequency Counter ranks single words, two-word phrases or three-word phrases, with a stopword filter, your own list of words to ignore, a minimum word length and a minimum count. Phrases never run across a sentence end or line break, and with the filter on, phrases that start or end with a word like the or of are skipped. It shows total and unique words, lets you sort and search the full list, and exports it as a copied table, CSV or PDF. It also handles accented, Hindi and Urdu text, not only English.
Pair it with the Word Counter when you want the totals and a quick keyword density check while drafting, and with the Reading Time Calculator to see whether the tightened draft also got meaningfully shorter. Repetition and length usually fall together.