Living with less is powerful and life changing when used correctly.
A lot of us spend a lot of time doing things that do not contribute much to our lives (besides instant gratification) like watching television, movies, buying and playing video games, drinking too much, excessive partying, and shopping.
What do you think you could do with all of that time and energy that you were using not only for that but for wanting new things, looking for them, talking about them, and working to pay for these things?
Everyone is different but in general we could be using all of this time and energy on things that would improve our lives (and our families) forever. Things like eating healthy, cooking at home, being with family, playing music, reading, writing, being creative, and/or building a business.
In general... Whatever your dreams are. When you no longer need, want, and have to pay for new things (be it cars, bigger houses, electronics, clothing, purses, whatever..) then you have created an abundance of energy (time, money, thought) that you can direct towards more important things.
I like to call it "re-prioritizing" life or "habit replacement". It's about sacrificing those instant gratification things and looking at the big picture (long term perspective) of what your daily actions are leading to.