When you reach Season 1 Episode 7, you will be introduced to the Action Queue. It allows you to queue up multiple actions by tapping multiple times. This will result in frenzy points, which is used to fill the corresponding gauge. Once the frenzy gauge is full, Super Gordon can automatically serve all his current customers. Use him when customers are backed up.
Coins
Instead of immediately swiping to collect coins on the tables (and earn frenzy points), consider leaving them until all slots are filled. You can then swipe to collect them all in action. This will prevent new customers from sitting down, allowing you to get more time and not be rushed. However, do not leave the coins sitting for too long or you may not have enough time left remaining to serve all your customers. After completing all the episodes of Season 1 you can collect your profits from Big Bay Burgers. These profits will accrue over time. You will receive a notification to show that they are ready to be collected. Do so to get coins and experience points.
Cooking
During the early portion, you will only have a single Grill Storage. This allows you keep one patty ready to server. When you can spare the time, make sure you place a patty on standby in case someone orders a hamburger. If you do not remember how to make a recipe, tap and hold the order bubble that appears over a customer's head. This pauses game play and shows you how to complete that specific order.
Trophies
Complete the task that a trophy requires to earn coins and gold bars. Save the gold bars to upgrade kitchen facilities in the latter portions of the game.