Of course someone like me should always read all the instructions first. I do that, but I find that often someone describing a lengthy procedure has not listed all dependencies or requirements such that they are all understood. For example, finding a line deep down in a described procedure that says something like "you must also have file xxxxxxx.xxx." Or getting to the end of a procedure and finding that something needed to be upgraded before I started.
I would suggest that all requirements and dependencies be listed first on a line or in a section which says that and lists them.