Sort of concocted from a few printed recipes plus watching a bartender on a Royal Caribbean cruise (the only good thing about that RC Cruise, mind you).

to a shaker add:
3 tsp of fine beverage grade cane sugar (a skosh more if you like it sweet)
a small bunch of mint leaves
1/2 a lime cut into wedgies and squozed into the shaker
Bacardi Limon (just an extra flavor thing) 2-3 shots

Use a bar spoon to mash/mull these well, breaking up the mint leaves.

Add 3 more tsp of fine beverage grade cane sugar (a skosh more if you like it sweet) and ice.

Shake the livin bejesus out of it (hopefully grindind the mint leaves into lotsa little flakes...yeah, it works...don't fill the ice up all the way...but REALLY shake the libin bejebus out of it)

Don't strain, pour the whole shindig into a tall glass.

Add a tiny bit of club soda to the shaker, swirl around to pick up any bits of mint, lime pulp and/or undisolved sugar. Pour it on top of the cocktail and mix it in.

Add a bit more ice if you desire.

yum.