Walking on ice without the necessary equipment (crampons and ice axe) is very dangerous and generally should not be attempted. In most parts of Australia, ice rarely covers a large area nor does it last very long, so avoiding it or waiting for it to soften are alternatives in most circumstances. If the ice is just a thin crust on the surface, then heavy stamping of the feet may break though and provide reasonably secure footing. This technique is not recommended for crossing wet boggy areas, and definitely not over lakes!