- When possible use a hardware wallet like Ledger Nano S or Trezor. Your crypto currencies are safe even if your computer gets infected with a virus.
- Exchanges get hacked and they sometimes have down time. Use two factor authentication and do some research on the exchanges.
- Online wallets are the only option for some coins. Make sure to use Chrome plugins with good ratings that can verify your online wallets ( example MyEtherWallet )
- Store the seed of your hardware wallet in a safe place. Store some of the seed words in one place and the rest in another place for example.
- When buying crypto/tokens. Only spend money that you can live without for a year, at least. If the crypto currency falls and you quickly need the money you have to sell at a loss.
- Do not post online how much crypto currency or tokens you have. There are reported cases of crypto currency theft IRL.
- Do not send crypto currency/tokens to people who claim they will double/triple/quadruple your investment. This is a known scam. In some cases people pretend to be famous people in the crypt space.
- Do not send crypto currencies, money or tokens to people directly . This goes for people who are not your close friends. Fake profiles are common. Once you have sent your tokens or crypto currencies it is very hard to get them back. Crypto currencies and tokens is not fully regulated and who are going to help you?
I am not a financial adviser and this is not financial advice. Use your own judgement.