I have forgotten what was written in Feeling is the Secret, but basically the title of that book says it all.
You have to “feel it real” in order for what you want to manifest. The subconscious and conscious mind cannot differentiate between what is “real” and what is “unreal” simply because it can only execute instructions and not make judgements. So, if you imagine something such that you can see, smell, taste, hear and touch perfectly, your thing will manifest.
Of course, with our conscious minds, that is often so difficult as there are so many barriers in our conscious minds that block quick manifestation.
That’s why for me, I just purchased a customized subliminal with Mind’s Eye and other manifestation modules set on Terminus to help me with lucid dreaming, where I can talk to my subconscious directly.