The window sign is like making a pane of glass with your hands. To sign window, form both hands flat, with fingers extended and together, palms facing you. Hold your hands one on top of the other, then move your dominant hand up vertically, apart from your non-dominant hand which stays put, then pull your dominant hand back down.
Teach your baby or toddler the window sign when you both happen to be near or standing by your window, peering out into the garden, yard, or street.
This is a useful flash card taught best when in the car or at home, as you teach baby to open or close windows or to look out for things in nature like birds.