Fill a highball glass with ice. Add gin, Campari, and vermouth to a shaker filled with ice. Shake vigorously and add to the highball. Top with club soda and garnish with the orange slice
For the Negroni Cocktail, omit the club soda and serve straight up in a martini glass. Garnish with an orange twist.
Serve, sip, sit back, deep breath, relax, enjoy.