We all owe him a debt of gratitude for keeping us safe, keeping us fueled with the petrol we need like our life's blood, making prescription medicine more affordable, sending a crap load of aid & $$$ to Africa to fight HIV/AIDS, for insuring that Israel did not go up in a mushroom cloud and for preventing WWIII.
Giving him oral favors won't be necessary (as some would have gladly given B.J Clinton or BHO).
A simple thank you and including him in your prayers will probably do.
He is a fine man and a credit to America.
History will be deservedly kind to his administration.
He really tried to do a good job for America.