I mostly concur with Mike.
I don't technically withdrawal my non-pension retirement money at this point. What I do is send quarterly dividends and capitol gains to my checking account. When I get to a point where I withdraw funds, it will be from the conservative portions of my TSP and taxable Vanguard accounts.
Rather than some set time, my withdrawals will be based on anticipated need. For instance, if I need a new car next year, I would now start looking at pulling some money from the conservative funds, while at the same time, given the current stock market, look at moving profits from the stocks to the conservative funds.
If your 401K is your only retirement source, quarterly withdrawals are as good a choice as any, IMO. If you're more willing to watch the markets, then you might do some "one off" withdrawals when the market is booming - again, using the current couple of years as an example. Or if the market crashes by 50%, that might be a good year to tighten your belt and spend less until the market begins to rebound.
A place to get some real world examples might be the early retirement forums:
https://www.early-retirement.org/forums/I'm only a lurker there, but I have picked up some really good ideas in the "FIRE and Money" subforum.
Also, if you use their calculator:
https://www.firecalc.com/Depending on how much money you anticipate needing annually, you might be at a point where you just pull money out whenever you feel like it as long as it's within a pre-defined max, since in most cases your money is only continuing to grow