I will be moving to a new position at the beginning of the year. The 'split' is comepletely amicable, since my current boss' laboratory will be moving to the other side of the country in the fall when the new academic year begins and he recognizes he can't expect me to wait until then to secure continued employment.
I've thought about getting him a 5 or 10 dollar gift certificate to the coffee shop in our building - which he patronizes regularly - partly as a Christmas gift and partly as a thank you for what he's taught me during my time in his lab. Gift-giving by a subordinate can come off wrong though and a verbal thank you would certainly be safer. I'm relatively new to the working world, so this is a bit of a dilemma for me. Am I being overly cautious on this, or not?