Keep the friends who ask “how are you, really?” and then actually wait for the answer.

The second half of that question is the rare part. Plenty of people ask; far fewer leave the silence open long enough for a real answer to come out. Willingness to wait tells you more about a friendship than frequency, history, or how much fun somebody is.

Think about who last let a pause go unfilled for you. Put time with them in the week rather than leaving it to drift. And try being the one who waits, the next time you ask somebody else.