Just dont get goxxed. Only keep on the exchange what you would use for trading. If you dont controll the private key, they are not your coins, but a mere promise from someone you probably dont even know.
People say this a lot in regards to bitcoin, but know one se ms concerned that we all accept the same risk with our fiat being held in a bank. If you keep your fiat money in a bank, technically you don't own fiat currency! You just own an greement that the bank will pay you back. Why is this when ch a gr ater concern with bitcoin?
A few different storage options is wise but don't get carried away if you have small balances. You're not a target for theft if your balance is less than a bitcoin.
I've been keeping more of my bitcoin with freebitco.in. Their interest payments are a solid deal....4% is very fair for my risk to of not having to the private keys, it's more than i get from Coinbase or Circle!