1. Take a shaker and fill it with ice.

2. Add the Gin Dry, Grapefruit Juice, Maraschino, and 4 drops of Angostura.

3. Shake the shaker vigorously for about 10-15 seconds.

4. Take cocktail glasses and pour the contents of the shaker into them.

5. Serve the Betty James cocktail garnished with a slice of grapefruit or a cherry, if desired.