Give people credit while they are present to hear it.

Praise delivered after someone is gone comforts the living and reaches nobody. The things you would say about a person at their leaving or their funeral are almost always things they never heard, and hearing them would have altered how they saw themselves.

Pick someone whose contribution you have noticed and tell them, plainly and specifically, this week. It will be slightly awkward. Do it anyway. Nobody has ever regretted the version where they said it in time.