As a profession; professionally.
tools of trade
The items and equipment that a person uses in the course and scope of …
by hook or by crook
By any means possible; one way or another.
by and large
Mostly; generally; all things considered.
by the skin of one's teeth
Barely; closely; by a narrow margin; with nothing to spare.
by the book
In a manner which strictly adheres to rules, legal requirements, or of…
by no means
Certainly not; definitely not; not at all.