A thank-you saying, such as "you have enriched my life by your kindness and generosity," is suitable for acknowledging a graduation gift. Other fitting phrases are, "I offer sincere thanks for the lovely graduation gift," and "thank you for adding to the joyful spirit of graduation with your lovely gift."
Gratitude is also proper for recognizing someone's presence at a graduation. An apt thank-you expression is, "it was wonderful of you to share my graduation celebration with me." Other thank-you sayings for attendance include, "words cannot express what your congratulations and generous heart meant to me during my graduation," and "during my graduation ceremony, it was wonderful to look out into the crowd and see you sitting there."