NEVER USE THE SAME PASSWORD TWICE
You need only one security breach to turn everything upside down. Use different passwords for all the accounts, if one of them gets hacked, the rest are safe.
If possible, always use 2-step verification. If your password is compromised, they still need to access your phone to get that second step verification.
2 step verification is one of the best security we can apply. they may hack your email and password but the phone you are holding will still the best.
USE A COLD STORAGE WALLET
If its offline, its hard to touch. For an extra layer of security use hardware wallets or paper wallets. Remember to lock them up in some place secure.
Not all people are into this, but this one of the best wallet where we can store it for a long time, safest!