Before going any further ask yourself if you are using a "check list" or a list of items that make up a procedure.
Pre-start- Check oil level, all clear, brakes on. Start engine.
That is a checklist....important items that must be checked.
Switch this on, pull that push the other etc found in most GA checklist are better desribed as "how to start the engine lists"
Using that idea and the full scan principle as soon as one sits down, checklists become much smaller and doing them is seen as less of a chore.
Of course, if unfamiliar then the "how to do it list" is required but not after that.
You will never miss anything off a written 3 item checklist. Make that 30 items and the posibility of a slip increases dramatically.
Personally, If going to the fuel pumps prior to flight, I would complete the walkaround prior to first move off - best chance of finding a reason not to taxi at all.
Agree with the checking of fuel both as part of the walkround and after fuelling. However, after refuelling it can take 20 minutes for the water to settle out of suspension in the fuel so a quick check straight after may not reveal all the water.
Of course the fuel check is not just about water it is about dirt and also the correct grade of fuel.
Suppliers of fuel are required to check the fuel by taking a sample each day. Ask to see the sample for that day - it will be in a nice big glass jar on the truck or stored near the refuelling point.
After refuelling, it is important to complete the pre-take-off checklist. (or taxi and power checks if to divide the checks). One of your pasengers may have decided to leave their handbag resting on the rudder pedals.
Regards,
DFC