Best strategy id seen so far in this past crash was this -
-BTC- always keep some handy ,actually now that its cheap is the best to pick up small amounts
Always look at the 1st tier of alt coins as well
-ETH/NEO/BCH/LTC...these held up pretty well in this downturn.
What i've learned is as long as you have BTC & some of those 1st tier alts...it isn't as painful as others when crashes occur