It's also a good idea to sand an angle onto the forward facing end of the bridge pins. This stops the ball-ends being caught so that they sit on the bottom of the bridge pin and not against the top. This either results in the bridge pin being pulled up by the string when you start tensioning the string, or the string slipping as it gets pulled off the end of the bridge pin once there is some tension applied.

The angle pushes the ball end forwards as it's inserted, so ensures it starts in the right position.

It takes seconds to do with a piece of sandpaper on a flat surface.

Before:



After: