Keep your funds in your personal wallet and not on an exchange, except while trading.
And it us advisable to stick to decentralized systems, where you own your private keys.
Yes its good to keep your funds in your wallet than keeping it in exchangers, but dont you think that even personal wallets can also be hacked? I have seen wallet providers complain about their security being breached. So no place is 100% safe (unless, maybe offline wallets can be safe from hacking) there are some security measures you have to maintain if you dont want to have your wallet hacked by these monsters.
We can't ensure that our money is safe on exchange sites. If you're have knowledge about security then you can withdraw all your token in exchange site to private wallet but this also can ensure that your money will quite safe. The best we should use the big exchange site like Binnace, Bittrex, as far as i know they are two site which have Security team extremely good and still haven't been hacked.
Hmmm, youre right in a way cause keeping your cryptocurrency in exchangers is kind of a risk. You should only have them in exchange whenever you want to trade with it, apart from that, you should have it stored in your personal wallet. But even if you have them stored in your personal wallet, you still have to be careful and avoid things like opening mails from an unknown sender.