Protect the people who protect your name when gossip offers them a cheaper friendship.

There is a real cost to defending someone when the room is going the other way, because gossip offers easy belonging and defending an absent person refuses it. The people who pay that cost for you are rare, and they usually never mention it. Noticing them and looking after them is one of the more practical forms of loyalty. It also tends to be reciprocal.

Think about who you know has spoken well of you when it would have been easier not to. Tell them you noticed, or simply be reliably that person for them. Relationships built on this kind of protection are unusually durable.