The following is a technique discussed in the book Making Peace with the Things in Your Life by Cindy Glovinsky. This book is packed with information on dealing with the Things in your life and how to determine which things are worthy of staying in your life. Give this technique a try:
“Choose a room in your home. List every Thing you can see in it that is not essential for your survival. On a scale from 1 to 10, how much pleasure does each of these Things currently give you? The items with a score of at least 6 are among your “happiness Things.” Now focus on the Things that receive a score of less than 6. What “shoulds” are motivating you to hang on to these belongings?”