Green’s Dictionary of Slang

tricks n.2

[backform. f. colloq. greeting how’s tricks?]

circumstances, one’s life.

[US]E.H. Lavine Third Degree (1931) 162: About an hour later, the sergeant came along and asked him how tricks were.
[UK]J.J. Connolly Layer Cake 104: Tricks are good but I ain’t got time to enjoy things.