How do you prevent ice cubes from sticking in a tray?

Answer 1

Leaving the tray of ice cubes out for a while before popping them out.
#1. This sounds good; however, in real-life the ice cubes melt.

cooking oil

Excellent suggestion; except, the ice cubes then incorporate the taste and smell of the "cooking oil". Which, may upset those who enjoy a Martini on the rocks!

You can also pour a little bit of hot water over the ice, and it will unstick.

Please see the results for #1 above.

When you refill the tray , let the tray sit until it comes to room temperature, then return it to the freezer. The next tray of ice won't stick.

I like this one, and will try it. Altho, the water I fill the trays with is already at room temperature as is the tray.