I downloaded a countdown app for my phone. It started at ~630 days. I do not even look at it any more now that I am FIREd. Most of my co-workers and bosses knew I was retiring and how many days I had left. It was almost a running joke. I was already very FI by that time.
I had a printed calendar on the wall. The first business day of the month was written in. When I got to under 100 days, I had a 100 day count down chart. And my monthly calendar had the days each week. Wen it was under 30 days, it was written down every day.
I checked my FIRE plan at least 5 times a day. Most days I suspect it was more. I zeroed in on the day, and the reason for the exact day. Be sure to account for pensions anniversaries, 401K matches, bonuses, holidays, etc.
Make damn sure you know the date you can leave without looking back. If you have to go another year, after counting down for several years, it will nearly kill you.
Keep a positive attitude. If you are not yet FI, and get laid off, that may also kill your life plans.
Focus ion the mental preparation. If you are just leaving to leave, know what you are leaving to Far too many people need the structure of work. And they cannot live normally without it. Depression, drinking, etc. all are risk factors of lack of structure.