Holding my coins on the offline wallets for long-term holdings. I think offline wallets are best for holding coins safe. For short time holding and trade, I hold my coins in different exchanges.
that is the most secure way of holding coins storing it on the offline wallets like hardware wallets, I have a worse experience in storing coin in an exchange, the exchange delisted the coin that I am holding for almost a year so it is not advisable to store coins in exchange for holding.