Use Hardware Wallet
One of the safest places to store crypto assets is a hardware wallet. These hardware wallets are items specially designed to store Crypto assets.
Hardware wallets have the ability to store users' private keys in a secure hardware device with very special features. One of the main advantages over standard software wallets is that they are immune to computer viruses stealing from software wallets.
In addition, private keys are often stored in a protected area of ​​the microcontroller, and because of this, they cannot be transferred out of the device in plain text.
Plus, because the software is open-source, it allows users to validate the entire operation of the device and how well it performs.
Popular hardware options include the Trezor or Ledger.

Use Multisignature
When storing large amounts of crypto assets, you should consider using a multisignature wallet address. Multisignature wallets are also suitable for companies that store crypto assets.
With multisignature wallets, multiple parties are required to store multiple private keys for one wallet. So people cannot take crypto assets without knowing all the private keys.
For example a wallet with 2 out of 3 multisignature means that the wallet has 3 private keys and to use the wallet at least 2 private keys are needed.