Tricks of the trade = special knowledge associated with a profession (os macetes de um negócio ou profissão)
Mr. Wilcox has been in this business segment for a long time. He knows all the tricks of the trade.
O sr. Wilcox está neste segmento há muito tempo. Ele conhece todos os macetes do negócio.
José Roberto A. Igreja is the author and co-author of several ELT books, including:
A BRAND-NEW ELT BOOK!
600 Phrasal Verbs (with Jonathan T. Hogan)
Fluent Business English (with Robert C. Young)
English for Job Interviews (with Robert C. Young)
Fale Inglês como um Americano (with Robert C. Young)
American Idioms! (with Joe Bailey Noble III)