My tactic has been simply buying more! This moment of down will pass and we will be happy to have bought on such great value.
I'm confident in a market recoup.
Yes, it is good to buy more when the market is falling then HODL and patiently wait for the market to rise and recover again. But you have to find out what is reason why market is falling before buying more. And check the potential of the coins that you are buying to avoid massive losses in the future.