What is your equivelant to the perfect pour?

In bartending there is a term known as a perfect pour. That is, if you are making up six shots of a mixed drink then, you mix just the right amount of each ingredient so that you fill each shot to the rim without having to either left over drink or having to make another small batch. This takes time to perfect, hence the term the perfect pour. I am wondering if all jobs have the equivalent to the perfect pour?