Take whatever steps you think necessary. I will say this. In 2200 hours
of flying all over the US, Canada and Alaska, I've never seen fuel
contamination with water nor have I had debris in my fuel filter. The
only problem I've ever had is the fueler NOT topping it off completely,
which if you are counting on flying close to your max range with full
tanks can be bad news. There are lots of accidents where pilots run out
of fuel. Do everything you can not to do that. Take whatever steps you
think is necessary. I try and watch the fueler or fill the tanks
myself. I check the gas caps (never had anyone put them on wrong
though).