Please choose one that you feel is the best solution when you have lost substantial value on your investments (or add another strategy to help out the community):

#1 Realize that you don't actually lose anything until you actually sell at a loss.  So you go outside, ride a bike, read a book, resist the urge to check coinmarketcap and just hodl.

#2 Come onto bitcointalk and whine and cry and find out what to do with your life.  When no one gives you clarity or direction, panic sell and lose your life savings.

#3 Start hedging your bets.  Put more money into similar projects or move things around to balance your portfolio out.

#4 Buy more into the coin you are losing money on while the price is low to reduce your overall cost per coin/token.  Thus making it easier to make back what you lost.

#5 Join a pump and dump group because those work 100% of the time with no losses whatsoever *rolls eyes*

Personally, when I first started out, I honestly did #2.  After I learned my lesson I just decided to hodl.  Now, I am making a more proactive stance on my investments and am doing #4 to much benefit.  Nothing melts stress away quite like actual results and making smart investment moves is always better than just passively sitting back and waiting for things to change.