Stay focused on people rather than objects that may be lost or destroyed; people are so much more important and our true value is not what we have, it is the person we are inside that others will respect. But in the same vein, pay attention to the fact that while materialism is not all of life, it is part of it. We all need things to survive, and while we always must remember that things are not everything and others aren't to be judged just on what they have, we must also keep track of our things and take care of them, conserve them and expect respect for our things from others.
Just don't get it in your head that things are everything. If you're obsessed with amassing as many possessions as you can, you won't be able to focus on growing as a person and building relationships.