We've filled up at a lot of different types of places following some basic guides, fill up early (at the 1/4 tank mark) so you can choose the best looking place, choose the pump lane with an eye for a clear run through and out even if it means waiting longer for the cars in front to clear, and of course don't forget which side your fuel cap is - the 'long reach' hoses often aren't long enough with the extra width of the van.
At services we use the van facilities, if we do leave it the hitch lock goes on.
If the steadies are used, the winding handle goes on the driver's seat - which makes it hard to drive off with them down
On a long run we also make sure we end the day with a full tank, makes for a more relaxed start on day two.