First of all, there is no guarantee in investment (my first rule). Even in other investments, there are no guarantees so if you saw the word guaranteed profit the best thing to do is to stay away from the investment because it will end up as a scam.
Some scammers' strategy is that they will put in your dashboard an amount which is twice the money you invested but in reality, you can't withdraw it because in order to withdraw it you must invest a certain amount. Best thing to do to prevent being scammed is either you learn how scammers scam people or just don't invest at all.
Scammers invent new schemes all the time. It's impossible to learn all of them. I think a good practice for the not experienced investors would be something like KYC, only in reverse. Being a customer, know the people you are dealing with. And when you know who are they exactly, read as much as possible about them on the Internet. Trusting your money to someone you don't know is a stupid act, so don't be surprised by the consequences.