Manifestation happens all the time. It is not something that we "start to do" when we become conscious of it, or our awareness expands. We literally do it all the time. Even "time" is an act of manifestation.
Now, in the paradigm we are leaving behind, we decided to have set, solid, agreed parameters manifested and locked into place, so we could have a very particular type of experience.
The new paradigm we are partly into has us consciously manifesting what we want to experience.
We do this by first deciding what it is that we want to manifest in our lives, and then using various tools to consciously do it.
The biggest and most essential of these tools is DAYDREAMING.
Everything that you see on the planet was once daydreamed. It then became "reality". And I am not just talking about technology, art, buildings, religions, ideologies, countries... and other "human" constructed objects and ideas. Even the "physical" ground you walk on, the trees, flowers, animals, the planet, the entire universe, was once (and still is) but a dream dreamed in conscious awareness.
So, what exactly is a daydream? Wikipedia has a lovely sentence to describe it:
"Daydreaming is a short-term detachment from one's immediate surroundings, during which a person's contact with reality is blurred and partially substituted by a visionary fantasy, especially one of happy, pleasant thoughts, hopes or ambitions, imagined as coming to pass, and experienced while awake."
I fully suggest you read the rest of that wiki daydreaming article, it will amaze you as to the effort extended to eliminating this particular skill from our world.
Daydreaming is often categorized as "fantasizing". The main difference between the two words is that a daydream has the "possibility" of becoming real, while the word "fantasy" has been designated the energy of "not real".
As a manifestation tool, this is how we use it:
P.S. for guided daydream exercises for your personal ascension do the Ascension101 Course.