… was hired by two different former clients.
One from six years ago.
One from I don’t even remember, it’s been so long.
In both cases … they contacted me.
In both cases … there was zero need for me to prove my capabilities.
In both cases … the “proposal” consisted of a few informal emails back and forth.
None of this happens, though, if you don’t invest at least some of your time in maintaining connections with past clients.