Having Trouble Buying in this Market?

You might be hesitating to invest because you are unsure how much further the markets will decline. It would be ideal to have a precognitive or clairvoyant ability that would allow us to predict the lowest possible price for a stock, buy it, and then watch the price soar upwards soon after making the investment. The problem is, to my knowledge, no one has demonstrated such an ability. So, what should one do?