Refuelling using Avgas, definitely check after each refuelling and first flight of the day.
Refuelling with Avtur. First flight of the day, however, usually the engineers have done that (if you're lucky). Water takes so long to come out of solution in Avtur that it is impractical to check after refuelling. Water in Avtur isn't nearly as much of a problem with Avgas. It's a lot harder to accidently leave the caps open on an Avtur powered aircraft (and let water in that way).
That's the beauty of turbine engines, they aren't as fussy as piston engines with respect to impurities in the fuel.