Place the oil and melt-and-pour soap in separate bowls. Microwave on high in 20-second intervals, stirring in between each, until completely melted.
Pour sugar into a medium sized bowl. Add the melted coconut oil and soap.
Add in optional scents or other ingredients of your choosing. Stir.
Quickly move mixture to a mold and let firm up (putting it in the freezer helps).
To use, simply take a cube into the shower with you and break up with your hands slightly. Wet the mixture ever so slightly, then scrub away!