Furistas Cat Cafe (Android)
CheatingDome.com
Do not rush
Don't rush - customers will wait at the door until you're ready to serve them.
Keep an eye open
Keep an eye on your cats while you're playing, as they might give you a bonus coin or two while they're not occupied.
Upgrade your cats
Upgrade your cats whenever you get the chance - they can still play with lower-level customers for fast rewards.