Not stopping at gas stations every week or so. I have a Volt that hasn't seen a gas pump since Feb 28 and my wife's Clarity PHEV hasn't seen one since June 17th. When I got my Volt I realized after about a month how liberating it is to not have to stop for gas in my daily life.
The roughly $1,000 a year I save in operating costs is nice as well.
2018 Honda Clarity Touring PHEV - Forest Green w/Tan interior (wife's car)
2017 Volt LT - Heather Gray; black bow ties, Charcoal VoltShelf
2012 Cruze ECO MT (hail totaled 5/8/17 103,600 miles @42.5 MPG)
2010 Mit Lancer GT MT (traded for ECO @31K miles)
2002 Pont Montana AWD - title to son at college graduation
1990 Pont Transport (traded for Montana @240K miles)
1986 Fiero GT MT (traded for Transport - needed more seats)
1985 Fiero 2M4 MT (traded for Fiero GT @8K miles)