Always upgrade your crops. This will increase the amount you get for each crop. This also needs to be done in order to unlock new pieces of land. Make sure to tap when upgrading to lessen the time. Selling your crops at the correct time is the most important factor in making a profit. At first it will be very easy to micromanage your crops and switch from one to another while waiting for a new customer to arrive. However you will eventually be faced with the long waiting times for each crop to become ready, and have a very large number of crops to care for. When this happens, focus on three or four crops while you are actively playing. Tap on them to max them out for when a customer arrives, and keep selling at the better price. Allow all the other crops to grow naturally. You can still sell all your products even if you do not have customers ready, but at a reduced price. To navigate through your customers, tap on their icon at the top left. Sell all the products that are ready when you are ready to leave the game. This will reduce crop spoilage and minimize your losses.