You can get 10 free diamonds by watching an advertisement video, and the best part about this is that you can watch as many advertisement videos for diamonds, as you want to, with absolutely zero limit. Simply go to the diamond store, and claim your free diamonds, then wait for 60 seconds, and you will be able to claim them again.
Additionally, you will be able to spend 10 diamonds on earning a stash of cash whenever you want to, so technically, watching videos for diamonds is also the fastest way to earn cash in the game, even faster than simply waiting for off-line income to pile up. Plus, the amount of cash that you get increases as you upgrade your restaurant.
There are three different ratings that you have to increase in order to upgrade your restaurant. The first is the facility rating, which increases whenever you upgrade furniture and appliances. This is fairly easy to upgrade and not extremely time consuming, but it usually takes longer than upgrading your staff.
The staff rating is the second category, and this can be increased by hiring new staff and upgrading your current staff members. Not only is this, arguably the easiest and fastest one to upgrade, but the more staff members that you have, the more that your restaurant can automate itself, and the more cash that you will earn while you are offline.
The food rating is the third category, and this is arguably the one that takes the longest to upgrade. In order to upgrade your food rating, go to the “develop” button to unlock new food, then go to the “menu” to upgrade the star rating on food that you have already unlocked.
As you upgrade your restaurant, you will start to unlock entirely new areas. For example, the VIP area becomes available after you hit Tin 3, and this allows you to build big, expensive tables, and accommodations in order to feed large crowds, so these are excellent for earning more money.
Once you hit Bronze 1, you will be able to unlock the arcade machine outside of the restaurant. This machine will allow you to play two different mini games in exchange for tickets. These tickets can then be traded in for prizes, with four leaf clovers and food elements being the main thing that you can find. Purchasing food elements will allow you to unlock new food far more quickly than just waiting for the lucky cat to give you ingredients.
Four leaf clover’s are useful because they will allow you to increase the tier rating of a specific type of food. This can be done once the food has been upgraded to five stars. The best foods to tier up first are the ones that are used most frequently; your absolute best bet are the broths, because they are unlocked so infrequently.
You can unlock new broths (and complete specific quests) by merging flavor bottles together. This can be done in the match game where you collect flavor elements. There are five different levels of merging for each different flavor element before you get to the bottle of extract, and this requires a total of 32 of the basic item.
For that reason, it takes forever for your broths to be unlocked, because you have to do so much merging in order to get each individual flavor element. Be sure to collect whatever the lucky cat picks up, though, especially if you have been off-line for a while, because often they pick up merged items.