I only want to point out, that you don't always get hypnogogic images and you still can get into a lucid dream. Waiting for something that may or may not happen can lessen your chances of getting lucid. HH are only one way to get there, but we don't really pick what will happen. Best to be ready for anything.

Also, to say that falling asleep takes certain amount of time, or anything else so structured may be misleading. What works for some, may not work for others, or it will work differently or only sometimes.

Best would be to understand the whole process to know why we do what we do, so we can follow some kind of a loose path without being concerned about some structured steps that must happen for us to have a LD. This is especially true for someone who is just starting out with lucid dreaming. Mental state and what we think is more important than what we do.