[janci]

Traditionally it was done here in eastern block with a beer bottle. A tool always within reach of a builder.

[leobg]

How do you make a round corner with a beer bottle? I mean an actual corner (three walls meeting), not an edge (two walls).

[account42]

Use the edge of the bottle base as a semicircle-shaped spatula and rotate the bottle as needed?

[Daub]

Beer bottles to make rounded corners? Brilliant!