To Have And Have Another

Yes, everyone around is drinking Hemingway cocktails at the moment.
Here is an easy guide to successful making:

2 oz white rum

1/2 oz ounce fresh grapefruit

3/4 oz fresh lime juiced

1/4 oz Maraschino liquer

a pinch of brown sugar

1 cherry, slice of grapefruit (optional)

Combine all ingredients except the optional into a shaker over ice.

Shake hard

Strain

Serve up with a cherry or slice of grapefruit 

Drink

Repeat procedure

Be happy