I really like this idea from Josh Brown about putting in good-to-cancel limit orders well below market prices in the event of market volatility. If you are afraid the market may crash, this can give you a mental edge to root for your favorite stocks to go down and buy at a much lower price. Check out the video below. He has written about this before too.
https://www.cnbc.com/video/2018/02/09/trader-josh-brown-on-how-to-deal-with-sell-offs.html
the counterfactual 