We don't eat out very often anymore.
Cook from scratch, not packaged foods.
Microwaves can cut down on energy use - less time and energy to het water compared to a stove top, less energy than heating up an oven. My microwave has a convection setting which is great.
Have weekly potluck dinners with friends. My college age daughter does this with their group. They rent a movie from the Red Box ($1) or play a board game. They get to try different food than they would usually make. Pick a theme and alternate who brings what course.
Skin kids - Jason, Kevin, Allison
Canine kids - Bennett & Bailey (always in our hearts), Riley, Banker, Rogue and Boz
Feline kids - Zoey, Talley and Abra