There are many unsafe illegitimate exchanges, which you must avoid and do a lot of research before trading or in any of the exchanges. You can ensure security in these ways:
- Use 2-factor authentication
- Try and use cold offline wallet. Having multiple cold wallets in a different place is considered a good idea.
This is bad advice.
Yes, there are plenty of shady, scam, illegitimate, etc., exchanges. Yes, people should avoid them. But 2FA and using cold wallets does absolutely zero to protect you from them. Any exchange, service, or website can institute 2FA with minimal effort. All that does is prevent other people from accessing your account. It does nothing to protect you from the exchange exit scamming, shutting down your account, or stealing your coins. Similarly, using a cold wallet is good advice, but to trade on a centralized exchange you must send your coins from your own wallet to theirs. It doesn't matter whatsoever where your coins have come from - once you have deposited them to an exchange, the exchange has complete control over them, can choose to keep them, and there is nothing you can do about it.
A hardware wallet is a viable option for the users who are concerned with privacy and security features as it stores the private keys.
A hardware wallet is good for security. It does absolutely nothing for privacy. If you want to be private when using bitcoin, then you need to utilize coin mixing techniques and care address control.