This method allows you to get 2000 coins every 50 mins, and without the need to feed your employees. The only downside is you won't get any points for leveling, since you won't have any customers coming in.
1. Get your reputation to 30 or above.
2. Set 2 employees to work with the rest of them sleeping.
3. Use anything to block the door. (this is so your reputation won't change)
4. Open the redecorate icon, menu, or go outside. Anything that "pauses" the game.
5. Get back into the game say around 50 mins later since the maximum you can get is only 2000 coins each time.
6. Change the employees since the current ones have low stamina by now.
7. Repeat.
Hope this helps :]