True creativity needs time to ferment. There are not many instant formulas.
A process that allows for experiments to be made, for false starts to happen, will produce the richest set of outcomes over time.
Given a short amount of time to come up with something, the first reasonable solution will be used. In an individual situation, the result may be fine. But over a longer period, short creative windows will result in ruts and repeats, a body of work that is far less interesting than the alternative.
If your business model is delivering the same product to diverse clients, then you are probably a commodity with little pricing power, so efficiency is your hammer. Use it.
But if your business model is to deliver unique results to varied and diverse clients, you are going to need time to generate all the ideas that don't work to discover the ideas that are genius.
That takes time. Fortunately its more lucrative than the commodity product.