There are two types of analogies, metaphors and similes. Metaphors compare two entirely different things, such as comparing the stages of life to the four seasons. They make the reader think and provoke deeper, more philosophical insights that add depth to your story. They are often difficult to come up with, which is why they’re so valuable.
Often the best time to gather ideas is during times of meditation or contemplation, such as during a walk in the woods, visiting an awe-inspiring location such as a National Park, or somewhere you seldom go that stimulates your imagination.
This is when the advise noted a few days ago to keep a writer’s notebook is worth its weight in gold. You definitely want to have them on hand when you need them, which might not be for a while.