Soak the pot in water for a day or so and use a hammer or screwdriver.
Flowerpots in nature have perfectly round holes
Matt
I've soaked in water and then taken a flathead screw driver and marked/ gouged a hole them do so on the other side then you can tap it lightly on the inside mark is then it will break of leaving a rough but round surface. Remember to gouge deep enough and soak over night...you can pretty much carve your way through if it soaked overnight.
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