Toss enough ice into the highball glass to fill it up.
Take 5 or so mint leaves and add them to the shaker.
Measure 1 oz of cooled mango simple syrup with the jigger and add it to the shaker.*see notes below if you don't have a jigger and need to measure with cups and tbs. Take the muddler and muddle the mint and mango simple syrup. The mint leaves should be partially broken up, but not pulverized.
Take some ice and add it to the shaker.
Measure 1 oz of lime juice with the jigger and add the lime juice to the shaker.
Put on the shaker lid and shake well until the shaker is cold.
Take off the shaker lid and put on the hawthorne strainer.
Pour the liquid from the shaker into the highball glass.
Measure out 6 oz of club soda with the jigger and add the club soda to the glass.Pro tip: skip the measuring and just pour the club soda directly into the glass to top it off. Take a few mint leaves and toss on top of the drink as garnish.
If desired, use the bar spoon to mix the drink together.