If to follow buffet's cues, it would be smart to save when valuations are huge so you can make acquisitions on the cheap side when correction moves through.
But today we live in a world where the way to make money is through regulatory arbitrage (Uber) or startups chasing risky business models. Additionally, accounting trickery is orders of magnitude more elaborate today, and high frequency trading may have permanently impacted traditional models of volatility.
Of course, this applies only to publicly traded companies. My overall point is that determining value from fundamentals alone is nowhere near as straightforward as it used to be.
The skill is in determining what high and low is - i.e. you do need to have a sense of what the asset is worth. The easy answer is - figure out what its worth to you. i.e. what level of earnings or dividend does it seem attractive, and then accordingly, what is too cheap and what is too expensive. Obviously, take into account debt and other liabilities if you can.
That's why its necessary to understand the basic business model.
The tricky part is the temperament to do nothing when others are in a frenzy. Only a few transactions in your entire lifespan will determine the vast majority of your performance.