How to express gratitude

Begin a gratitude journal.
Expressive writing, such as journaling, can help you process negative events and emotions while also focusing on the positives in your life. You can develop a stronger awareness of what you have by making a habit of gratitude journaling, which may help you become more resilient to stress and hardship. There is no correct or incorrect way to keep a gratitude journal. Some people keep a simple list of things they're grateful for each day, while others may prefer to keep a longer journal.
You could begin your gratitude journal entry by noticing how you feel in your body and mind. Then, try to think of 5 to 10 things for which you are grateful.

Make it specific.
Identifying specific, small things that improve your life is an essential component of any gratitude practice. When expressing gratitude to someone else, it's also a good idea to be specific. Rather than simply saying, "I'm grateful for all of your help," you could discuss a specific occasion when they alleviated a burden for you or quote a piece of advice they gave you that was extremely beneficial.

Please return the favor.
In an ideal world, people treat others as they would like to be treated. So, if someone has been a source of support for you, chances are their behavior reflects how they expect others to show up for them. Consider the specific ways a person has enriched your life, and then consider whether they might require the same level of assistance in return.
Then, try your hardest to follow that same "golden rule" and pass it on.