Make sure windows and doors are covered

A day or two before leaving or Storing empty the refrigerator and place something in the door(s) to prevent them from closing

Close all Vents Ceiling and Walls

Plug-up all drains and sinks with wadded paper towel or rubber plug to avoid insect entry

Put a teaspoon of Bleach in the toilet and place a piece of plywood over the toilet bowl

Wrap and SECURE plastic trash bags over exterior of Air Conditioners and Swamp Coolers

Turn off Propane and Electricity at source

Turn off water at source

Close sewer Gate Valve if applicable

To prevent corrosion and fire , remove all batteries from tools, clocks, remotes, etc. and store in coolest space you can find

Close and lock all Doors and Windows

If in warm/dry Climate, you can place numerous 5 gallon buckets filled 3/4 with water with lid (drill several 1" holes in the top). Usually place in the tub, shoer and or sinks to avoid condensation or leak damage.

 It's a good idea to provide a trusted neighbor, friend or manager with your contact information and a key to your unit.