I know you aren't supposed to, but I leave the engine running and stop filling at the first click of it off.
The way I see it, this lets the gas pump (nozzle) suck whatever vapor is caused by the engine running, and the fuel gets added to the engine more in real-time.. whatever infinitessimal amount that is.
The gas gauge fills up in real time, nothing even risks getting spilled out as I don't cram more fuel in there (and the station in Dorchester added another $2 once, so, whatever,) and, sure, some will call that a "bad habit," but.. Why put that wear/tear on your starter?
I also alternate tanks of 89/93. I usually gas up when it gets to half, or 1/3.. so I am always adding between 6 and 10 gallons, approximately. (18 gallon tank, approximately.) Could be either or, 89or 93.. 93 is $3.55 a gallon and it will take about 10 gallons this time, so the next time I will do that again with the 89. Switch (93..) Switch (89.) Repeat..