Be sure you have a weighted base, either the batteries or something else with some weight. You might tilt the animal back slightly for viewing and stability.
Turn the switch on the battery pack from OFF to ON. And enjoy your luck!
Going Further
You can use the Lucky Cat as a template for many projects. Add LED / LCD / OLED eyes, sound, whatever suits your fancy.
Check out Maneki Neko Defcon (Twitter @ManekiNekoDC) for the design below with multi-segment eyes in the style of #BadgeLife, an A+ Lucky Cat.