I'm 39 now, but I started this path late. Most of my life was spent going from country to country, with all of my possessions able to fit in two bags. I was also reduced to the shirt on my back a couple of times in business ventures gone wrong.
What I've discovered is that there aren't actually
that many things to get. A bed, a dresser, a kitchen table and chairs, a couch, a coffee table, a TV, stand, amp and some speakers, living room chairs, a desk + chair, a bookshelf.
After that it's outfitting the kitchen and bathroom, clothing, and some art for the walls.
That covers the necessities. Beyond that it's just supporting your hobbies & things you do for fun.
The other 2% are things like a car (I just use Zipcar for now), some of the more high tech gizmos for the kitchen, more camping gear, good pots & pans once I get better at cooking - Stuff I can live without, so I'm content to wait for a really great deal before buying. The best part is finding something you know you'll need eventually (because it's on your list), but it's available now at a deep discount because some shopkeeper is desperate to be rid of it.
That's actually the key: having the ability to be patient. For about a year, I kept a list of everything I wanted to buy, including links to what were the best in each area. Then I'd keep an eye out for sales, check out garage sales & flea markets, go to second hand stores, surplus stores, etc. I tried to not buy unless I could get it for 70-80% off the new price or better, while still of acceptable quality. For brand new stuff over $50, I'd usually only buy at 40% off or better. To completely furnish my place with stuff I'll never replace, I spent about $2000 over the course of a year. Some stuff was free. Some stuff was damn near free (my solid oak desk was $20) Some stuff I ended up paying a fair price for, because I would accept no substitute. My biggest purchase was a 50" TV for $500, which I'll keep for the next 10 years or so unless it actually breaks. My older, 8 year old 32" TV I now use as an external monitor. It still works like the day I bought it, but then again I also researched the shit out of it before buying (Sharp Aquos, on sale 40% off).
The best part about buy-it-for-life stuff is that a used item is just as good as a new.
The research is slow and tedious. The key is to not be in a hurry. There is a finite amount of stuff to get, and you can probably survive without it for awhile.