The best retirement strategy is to have kids who wind up really rich. Oh, and make sure to treat them right as they're growing up. I know a few people who've accomplished this.
The second way would be to make sure to become rich yourself, either through work, investments or inheritance. Or pick a public service profession with generous retirement benefits, (this would have been in the past but it's worked out great for a lot of people).
The whole retirement question is such a moving target. Most living expenses, like food/shelter/energy/healthcare are rising steadily and not predictable expenses. As others have astutely pointed out, one catastrophic illness or economic calamity can wipe most people out.
My parents wound up ok through a combination of good incomes and buying houses in affluent areas that appreciated quite a bit, (plus investing heavily in vacation property that went bananas), they also don't believe in debt or pulling money out and have no mortgages. They are now in their 80s but this has been the case for 20 years or more.
For anyone actually paying attention, I refer to my mother and stepfather as my parents, my dad died in the last year and he had a really good county pension and benefits from being a retired judge. He also was diagnosed with cancer one month after retiring @ 70, he lived another 12 years and would have been wiped-out quickly without the health insurance from his job. So that was luck.
My older sister retired 6 months ago at 56 and moved to a small village in the mountains of northern Italy where she will pursue her passion which is being a bicycle racing blogger and riding a lot herself. I'm sure that she will travel a bit as well. She is not rich but saved her money, lived alright but not extravagantly and had a decent job. Never married and no kids. A certain rich sibling kicked in some on this deal.
I myself will just work till I drop and hope for the best. I'm trying to make an investment plan but starting late. I will be working at something forever and I'm ok with that. I don't golf or like motor homes and the idea of traditional retirement does not appeal to me on any level. Conventional life in general does not appeal to me, so this is not different. I'd rather be a hobo hopping trains and smoking hand-rolled cigarettes than to wander around some god-forsaken slab of concrete in the sunbelt as the earth gets hotter every year like Tabs.