Set a clear beginning and end step for your chosen process and then fill in the main steps in between. So for example, if you chose your morning routine it may begin when you wake up and end when you leave the house. Steps in between may include your bathroom routine, making breakfast, and driving to work.

You should have at least one Input's and one Output's for each process step. This should lead in most cases to one Supplier and one Customer for each Input and Output.