Well, you don't. Youu just continue to shove money your savings account until a relative dies.
I live in Cambridge, earn a nice chunk of money and choose to rent rather than move to a town 20 miles away from work which I might be able to afford a flat. The reason? To the north, you have the A14. A carpark in the morning rush hour, sitting there with all the other people who bought outside the city to commute to the Science Park. To the south, you have lots of pretty villages which are v v expensive, where people like Tom Sharpe, Germaine Greer and Jeffrey Archer live. To the East, thar be Fenland dragons and Norfolk. West... the motorway. I refuse to buy in at this point. I'd rather be in the city, be able to cycle to work, and do rowing and whatnot and be able to save up. Given the way the markets are behaving at the moment, I think you'd be mad to buy in right now where I am. I have a feeling we're all going to get a lot tigher soonish. The rates will go up and it'll be too much for those who've bought in, they'll sell, prices drop, etc etc etc. You know all this.
Ahem. So, no I don't know how normal people afford to buy houses. Because I can't and I earn more than median.