Cut up your strawberries and half of a lemon into pieces and add them to your cocktail shaker.
Use your muddler to smash them up really well, until the as much juice as possible comes out of the fruit.
Add in the grenadine and the non-alcoholic gin.
Fill the shaker with ice and shake everything well, about 15-20 times.
Add ice to your serving glass and strain the drink into your glass.
Top off the drink with the lime seltzer.
If you are making the garnish, use your cocktail pick to skewer the lemon slice and strawberry. (I wrapped my lemon slice around the whole strawberry kind of like a mini taco.)
Optionally add the garnish to the top of the drink, and serve!