With consistency, you learn from your mistakes and improve, you learn from others and apply them, you create your systems... my experience is like that. It's rare to achieve something significant by making only an initial effort or a good initial choice if it's not accompanied by consistency, but of course it requires good choices and effort as well.
Good choices in business are essential; changing if you make a mistake, always improving, knowing when to stop if things aren't going well... It's always better to work smart than hard, but it often requires effort to be able to do it; being consistent requires effort... I think consistency includes both: good choices and effort.