You need all that you can to survive and nothing more. You should make enough income to be happy up to the point to where it no longer brings you anymore happiness. I've found this to be around between $50k-$75k depending upon the size of your family and where you live. Some say you need considerably less and others say a little more. As you'll see in the video below chasing more and more money just makes you more and more miserable, not happier.
If you're not quite ready to go full out with a "packing party" then try just setting a huge box for stuff you don't use. I did this when I moved. I realized that I double and triple of certain things. Not necesarily that I had bought, but maybe just stuff that was left at my house. Too many cups, cutting boards, can openers, clothes, etc. As you find these things, put them in the box. When it's full, sell off as much of it as you can. If you can't sell it, donate it. Be sure to get a receipt if you itemize your taxes!