Use exchanges only when you are trading, otherwise move into paper wallet or hardware wallet (trezor or ledger wallet).

If you are trading use trusted exchanges like bittrex & binance or even poloniex with 2-factor authentication on your account.

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Notes:
1. 2-factor authentication is very very very important

2. when you backing up any important keys online try to hide 1/2 letters/words,
 e.g (key: 56dfd4fd654fd54f6d4f4ds4 - to:  56dfd4fd654fd54f6d4f4dxx)  hit = my first smartphone or any

3. when you creating any important key e.g myetherwallet or setting up 2-factor authentication on your account, you should disable all browser extensions and open "new incognito window" on your browser.