Via mhsteger, a few of Sydney Smith’s prescriptions for low spirits, from a February, 1820 letter to Lady Georgiana Morpeth:

6th. See as much as you can of those friends who respect and like you.

7th. And of those acquaintances who amuse you.

11th. Don’t expect too much from human life—a sorry business at the best.

14th. Be as much as you can in the open air without fatigue.

15th. Make the room where you commonly sit gay and pleasant.

17th. Don’t be too severe upon yourself, or underrate yourself, but do yourself justice.

18th. Keep good blazing fires.