Gather your ingredients: Choose your favorite soda base, your preferred flavored syrup, and your creamer (half-and-half or heavy cream).
Fill your glass generously with ice cubes.
Pour your chosen soda over the ice, filling the glass about three-quarters of the way.
Slowly drizzle in the flavored syrup, allowing it to settle slightly.
Gently pour the half-and-half or heavy cream over the soda. It will create a beautiful layered effect.
Stir gently with a long spoon or stirrer to combine the flavors. Don't overmix!
Add any optional toppings like whipped cream, a cherry, or an extra swirl of syrup.
Serve immediately and enjoy your custom dirty soda!