It is something I started to do a couple of years ago. Get rid of the old crap. You will feel so much better. It will also bring new exciting stuff/people in your life after you are done.
You have old relationships that were going nowhere but still seeing those girls from time to time, not forcing yourself to meet new people?
Get rid of them. Do a clean up and erase their number and meet some new people.
You have old crap laying around that you haven't used in a year?
Sell it on Craigslist, give it away or recycle it.
You have old clothes or books that you will never read again that are just taking space?
Give it away. There are a lot of people in need.