You can start to create your algorithm from scratch beginning from your basic thinking, from your start idea. You should write down what is your idea. Then you think what is your second stage and you should create arrow sign before you write down your idea or your next steps. The similar way you apply for your third step.
As the result you have your idea, for example like on the below diagram:
Create Pattern ===> Draw a Pattern on Paper ====> Cut the Paper
After you create your basic algorithm for something like to create or build or certain project or certain business, then you analyze your algorithm. May be after you think again your step diagram is wrong then you revise your diagram as your new idea. For example you apply Design first before Create Pattern on the above example.
Design Pattern ====> Create Pattern ===> Draw a Pattern on Paper ====> Cut the Paper
The pattern on the above diagram still on the paper, so if there is a mistake design, you can through away, and begin to create new design. For example on the above diagram you will form cut paper then you make new algorithm on the above diagram and then there are correction design if the formed is not right. Then you make your diagram as follows: