I dislike drilling holes, as it irreversibly damages the wall. Therefore I am very careful not to make too much of them. And in the cases I think it is unavoidable, I like to make as tiny a hole as possible. However, I'm not sure which minimal diameter is needed to withstand the force the screw applies on the plug an the wall.
How can I know the optimal size of the plug for a particular purpose? Which factors do I need to take into account?