Having retired here are some things I wish I would have done differently
1. Keep a meticulous budget and find out exactly how much it costs to live comfortably
2. Subscribe to a retirement planning program and determine how much you will need to sustain that standard of living. I didn't find the MaxiFi planner until after I retired but it was exactly what I needed to know how much I could afford to spend each year to maintain my standard of living and not have my money run out before I do. It has the State and Federal tax codes built in, the social security rules built in, and even optimizes when you should make withdrawals from retirement accounts.
3. Once you retire put your savings into some sort of inflation protected investment like I-Series savings bonds and the rest is on cruise control.