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!
Read up this advice since these are the basic things you do need for you to be on a good track.Always decide for yourself not just easily believing into other words because most likely you would really commit mistakes because of this one.
If you want to trade wisely you should make your own mistakes and look for ways to escape from them. After many mistakes you will have more experience - and you will begin trade wisely.
Making mistakes are dumb thing to do, you rather do the things that you can avoid mistakes but as a newbie or even professional ones avoiding mistakes is not possible.Therefore,make a learning for those things so that you would able to reduce the risk on next trades.