The faster you find the objects, the higher your score will be. You also lose points for tapping on the wrong item, or where there is no item, so go fast... but not TOO fast.
Sometimes, when you find an item, you'll see a suitcase pop out and fly up to the top of the screen. This means you've found a special bonus. At the end of the scene, when your score is calculated, the rewards from these suitcases will be revealed as well.
If you are struggling to find something on the list, tap on the light bulb in the bottom right corner for a hint that will highlight an item from the list. Hints are free, but they do take some time to recharge after each use.
In each scene you can earn up to five Stars, each one requiring more points to earn than the previous one. Earning Stars allows you to progress in the game and uncover more of the story. You will also find clues in the Hidden Object Scenes. The first time you play a new scene, you will find the first clue. You will uncover the second clue when you play a scene after earning your third Star in that scene. Clues are important to advance in the story, so make sure you find them all.
Each chapter contains five Hidden Object Scenes and a final Adventure Scene. To unlock new Hidden Object Scenes, you need to collect enough Flowers by decorating Orchid Island, and then find the two clues in the previous scene.