Personally, I for myself identified some good thoughts:
1. Do not invest all funds in one currency
2. Before you buy something, then study the coin in detail.
3. Do not listen to advice, but think with your head.
4. Do not keep funds on stock exchanges, but transfer to cold wallets. (If you buy in the middle or long term)
5. If there is a financial opportunity, then buy a separate computer / laptop for bidding and wallets. Your money is always at risk, do not go to phishing sites and pages, always check them!
This is very good suggestion but every person has their own and you should look for your own preference for your portofolio and become wiser.
For me, above is good to use as big factor to trade wisely and i add small addition, that is we should invest how much you can afford.