1. I always like the idea of " not selling everything ", assuming I have 1000 tokens I always sell 90% even when they are at ATH, leaving very few coins and tokens behind do have it's time, there will come a time where they add more value, remember not every ATH is the last ATH.
2. little coins that earned through airdops in 2017 they are not even close to 1$ and in January 2022 two of them did wonders, name is Avinoc and whackd token, I made 80$ from avinoc and 500$ from whackd, my main point here is if those coins have huge value at the time I would have sold them right? I took my eye off them because they have too low value...
It can be pretty tough if you are holding tokens in your wallet that you know of that you bought it for 1000$ for example but they are only worth 100$ at the moment or so, but i really think you need consequent here and don't sell those coins because once you have sold them you rally made the loss a reality. If you just keep hodling and wait for another few months or even 1 or 2 year then it is always possible that you will see prices like the one when you bought the coins or even higher ones again. So if you don't desperately need the money it is always good to hodl and wait for better times in my opinion.
It is also true that some dead coins might experience a sudden increase in value out of nowhere, then you need to be ready to sell of your airdrop coins because the price will probably go down again very fast.