I think the most secure trading is to use some money from trading capital and use money that will not be in use for the near future,
for example I have $ 1000 and I need to use the money for my family's living needs, then I can use $ 250 for trading and the rest to survive, do you mean from this revelation?
this method is used so that you are not too depressed if the money you have stuck in the expensive price.
In my opinion, that is not the best way to trade safely. I think you should list the book carefully and extract some money that you do not use in 2-3 years. That will be the amount of money you need to invest, since you will not have to worry about that money when you have enough money to pay for living.