You can also create and try different strategies on your own money, but almost all of them are also unsuccessful. You can understand this only after playing a lot, and if the strategies are very unsuccessful, then the loss of money will be very fast. It happens that some players, having come up with a strategy, do not want to test it with small bets, but are ready to bet everything on it, even take borrowed funds, which of course does not look like the smartest thing to do. Ultimately, it is better to test your theories on small bets, without borrowed funds.
Well, taking borrowed funds to test strategies is a very risky act, I really wouldn't do it, it seems to me that it is too much and it is beyond my limits, but to do that it is better to do it with a demo mode, with the demo mode you can do something like that without any problem and you can perfect it, so when you go to make a bet with real money you do it in a safer way, of course that is Something they don't do, they always test it with real money, but as I said before the risk is too much and Personally it would hurt me a lot to lose even 1 usd.