And that, I'm afraid, is the inevitable collision between sensibilitiy & practicality.
Being sensible means filling them after flight to minimise the risk of condensation.
Being practical means leaving them half empty for the next person to decide how much fuel they need.
Pre-flight, I used to shake the wings to move any water droplets down into the sump and then drain the fuel, by which time the nice chappie with the fuel bowser had arrived.
As a matter of interest, how many pilots have had water in their fuel testers? Is the problem more due to badly fitting fuel caps than condensation?
The Koliber had a very effective rubber bung sealing the filler neck and a metal flap over the top of it. We never had water in the fuel.