This question has options. How would someone go about accomplishing this goal?
How do I vibrate the concrete when pouring a concrete marble countertop?

Select from the following.
[1]. You can use a commercial concrete vibrator or you can rap a utility knife along the bottom and sides of the mold.
[2]. You can use a commercial concrete vibrator or you can rap rubber mallets along the bottom and sides of the mold.
[2].