Question special

Thank you all for your collective wisdom and guidance during this Q&A! As we wrap up this panel, it seems fitting to talk about expressions of gratitude. While a simple thank-you at the end of an email often feels insufficient, an all-expenses paid vacation (which may feel proportional to the difference a mentor has made in our lives) seems inappropriate. What is the correct balance for expressions of gratitude? And, if differing, how might we figure out the appropriate balance for each of our mentor-mentee relationships?