Gratitude is the gift you give yourself
Cultures throughout the world set aside a special day of the year or an entire season to give thanks.
For example, in North America we celebrate “Thanksgiving” in October for Canada and November in the United States. China celebrates the Mid-Autumn Festival, Germany has Erntedankfest (Harvest Festival). In Japan there is the celebration of Kinrō Kansha no Hi (Labor Thanksgiving Day), Vietnam has Têt-Trung-Thu Festival and India celebrates Pongal. All countries include some kind of ritual as part of their annual celebration.
And although dedicating a day or season to express appreciation is a wonderful way to practice gratitude, I believe you can express your thanks more often with a sense of ritual as well.