Chapter 11 is about keeping your material life in balance. Human nature can make this a challenge. It is easy to get excited about bringing new things home, not so easy to get excited about taking out the trash.
Your possessions can grow out of control just because you buy things you have already. That is, there are things you buy that you do not really need because you have many other things of the same kind. You can keep this from happening by using the Replacement Rule.
I suggest you adopt the Replacement Rule for categories of possessions in which you know you already have more than enough things. The Replacement Rule for a particular area of possessions says you must discard one of the old things for each new thing you bring home. For example, if you already have plenty of pots and pans, the Replacement Rule for pots and pans says you cannot buy a new frying pan until you decide which of your old pans you will throw away to make room for the new one.
The Replacement Rule is especially useful if you have a pattern of buying things just because they are on sale at amazingly low prices. When you have to stop and think about which of your current possessions you would throw away, it gives you the chance to ask how the new item would actually improve your life. Alas, the answer is usually that it would not, and it is better to realize this before you buy the item than after.