I think it would be fair to say that most people haven't thought very much about what "creation" is, or might be; beyond either assuming that there is really nothing special about it, or assuming that it is a wholly mysterious "black box".
And I believe that there is truth in both of these perspectives - in the sense that (while some particular Beings are much more often and more intensely creative than others) potentially all Beings are creative in some degree and way because it is an attribute of being-ness; while there is an irreducible mystery in being-ness, including the creativity of any particular Being.
My long term interest in human creativity and the phenomenon of genius was behind the process of thinking that is recorded in my blog Intelligence, Personality and Genius; and which culminated in The Genius Famine book (co-written with Edward Dutton).
In these books I both assumed that creativity was, on the one hand, on a quantitative continuum among humans; but also that some humans had a lot more of it (i.e. the qualitative category of "geniuses"); and this was related to a characterological (or 'personality') trait of the Endogenous personality.
This I envisaged as a type of person whose attention and motivations were highly-innerly-generated (rather than being in response to external stimuli) - endo-genous can mean "generated from-within".
(The Endogenous personality also explains many of the characteristic unusual personality traits of geniuses. On the one hand; there is not one standard genius personality type, on the other hand, the various unusual traits, as well as the averages for geniuses as a group, can be understood as various expressions of an unusually strong domination by innerly-generated motivations.)
However, these writings of mine were within the field of science, and did not, therefore, address the ultimate questions that lie out-with science. In particular, the origins of creativity were not mentioned.
Science cannot, of course, discuss where creativity comes-from, except to assume it comes from the other entities and phenomena that are a part of science.
Therefore, the best theories of creativity in science can only assume that creativity is a process of selections and recombination, interpolation and extrapolation, of what is 'already known' to science - and that the genius is therefore someone with exceptional ability to generate 'random' hypotheses from pre-existing materials, and then rapidly to sort-through and evaluate them.
The assumed process of creativity therefore (and not by accident) resembles natural selection: undirected generation of variants, followed by a selection among these variants, based upon some functional criterion.
But it can be seen that such a notion of 'creativity' means that there is ultimately nothing really new about what is created. From the perspective of science; all creation is (by assumption, hence by definition) just selection, recombination etc.
Such an idea of creation fits-with the understanding of classical Christian theology which draws a qualitative line between God-The-Creator (the one-and-only creator of everything from nothing, in a once-for all act); and Man the "creature" whose creating can only be a matter of selecting and re-shuffling what already exists in God's creation.
Thus God is the only really-real creator, and Man can only mimic divine creation in a kind of 'paint-by-numbers' process; as a creature wholly made by God and using materials and instructions provided entirely by God.
From this point-of-view; divine creation is a done deal: it already contains everything, and therefore cannot be added to.
But if we consider the creative act itself, and assume that there must be the possibility of genuinely original creation - a creation which does indeed make something new; then we come down to the idea of creation as a property of any Being - much like life, consciousness and purpose are other attributes of a being.
In other words, we can (it is possible, if we wish) assume that creativity is one of the attributes of all Beings - including God and including all other Beings.
And that is, indeed, what I assume!
But what is creativity?
In the first place, it can be defined double-negatively (using terms form medieval Christian theology), as an example of uncaused cause or a first mover.
Another, more positive, way of thinking about it; is that genius is "generative" (as the etymology implies) -- that is, genius is a kind of "spontaneous generation", originating in a Being, whereby what emerges could be regarded as an expression of the Being from-which it emerges.
It is also helpful to remember that Beings were unembodied spirits before there was incarnation. And, if we assume that spirits (as Beings) are potentially creative; then the primary kind of creativity is thinking rather than doing something to the material world. Genius relates primarily to thought, not artifact.
(But, by the same account; this concept of thinking is real, thinking is a part of the world; such thinking has an effect on the world.)
This clarifies that the essence of a human creative genius is not a book, painting or a piece of music; but the thinking from-which an artefact may, or may not, later be derived.
At the end of this line of reasoning; I arrived at an understanding of creating which includes divine creation and also the potential creativity of Man and all other Beings - God, Man and Beings within a single reality to which all these Beings may (in principle) contribute their creativity.
Such creativity is potentially originative, generative, genuinely novel - such that whenever God 'enlists' another unique Being into his creative project, that will expand the possibilities of creation-as-a-whole.
And - because creation is originative in each Being; this understanding makes of creation something potentially open-ended and everlasting. There is no reason why creativity would ever 'run-out'; since it is (potentially) an attribute of any Being.
This also fits with my other understanding of the nature of divine creation as being a process of exactly such 'enlistment'; a process of God creating the universe by securing the harmonious cooperation of other Beings.
I imagine the primordial situation ()before divine creation) as one in which each Being pursued its own unique and selfish creating; so that the whole did not add-up to anything - the individual purposes just 'cancelled-out' each other.
God's first act of creation was (by various means, differing through history) to 'recruit' more and more Beings to his creative project; so that these Beings began to share purposes and to cooperate in these purposes.
The principle of this cooperation was what we call Love.
Loving Beings align their creativity towards the fulfilment of Love - and this is why Love is the very heart of the Christian understanding of God.
So, an interest in human creativity and the phenomenon of genius - which preceded my conversion to Christianity; ended by feeding back into my core understanding of the metaphysics of Christianity and the human condition!