Staying updated always is the main hodl strategy. Many projects have migrated to its own blockchain of recent and some persons have been left behind during these migration. If you want a long term hodl, hold few tokens you can always monitor their development progress.
It's very important to select the right altcoins to hold for long term in the market and not all can survive for huge drop of bitcoin. It's difficult to hold altcoins for long term and sometimes it will test you if you're going to sell it or not so in order to support and not be able to sell you're coins, you need a consistent income to support it. I'm holding altcoins that are platform connected or have a crypto exchange, I believe that it will be safer to hold rather than other platform in the market.