It's only ever clever in hindsight. It's possible the best move right now is to buy 3x levered NASDAQ ETFs. And in hindsight it will look genius and obvious - market is down, buy levered ETFs. But the fact the market is down so much and you're now thinking about shorting kinda explains why it's not easy.
Also, bare in mind the only way to make money from a short position is to know when to sell - so how much further do you think markets will fall?