If you're going to write about how to jump-start a dead car battery, don't start with hooking up the cables. Equally important means equally unimportant. Attach a special warning to one of your steps. If you don't connect the positive pole to the positive pole of the batteries, you could cause an explosion or melt down your battery. As you write your essay, be watchful of your pronouns.
Consistency is the chief virtue here.
There is, of course, a difference between a process essay that tells readers how to do something and a process essay that describes the process by which something gets done by someone else or by nature. You could write a great process essay describing what happens when Mother Nature decides it's time for trees to lose their leaves in the fall. Neither you nor your readers are actually, physically, involved, but the process is fascinating in its own right. Here is a simple process essay on how to retrieve an e-mail message in the computer labs. It doesn't do any good to know that there is help available online because you can't even start the machine, and it's embarrassing to ask lab assistants who are busy helping others with complex spreadsheet questions.