Don't buy it until you can afford to pay cash. Get rid of all the insurance policies that are driving up the cost of everything and keep a slush fund in the bank to cover disasters. Focus your free time on outings with your family instead of shopping at the mall for more things you don't need.
Obviously you need a home, transportation, utilities, clothing and food as the basics. From there it is recognize what you need verses what you want.
Have the serenity to accept the things that you can not change,
The courage to change the things that you can,
and the wisdom to know the difference. <}:-})
I don't think it's really possible to live simply in today's society. Even the very basics aren't really "simple". I suppose you could go live in an Amish community and commute to your job.