Beyond hardware wallets…next step for security (looking for good reading/vids)

Hi all

What is the next step towards securing ones btc after getting a hardware wallet? I know there are multiple levels of security such as multisig. How can I learn more about different levels of security and slowly start to incorporate them? Does anyone have some resources to share that kind of walk through the different levels or steps towards approaches increasingly more secure than having possession of ones btc on a ledger?

Thank you ????