Good pointers indeed but most beginners today are not used to read every cautions before doing trades.
So for me, I want to see them experiences those losses in the early phase of their trading journey so that in the future they will do something to prevent or minimize it. Their experienced will lead them to automatically known those pointers above if they are really eager to pursue their trading career.
As mush as we want to help newbies to experienced mistakes, it can't be prevented. Sometimes to become professional, you must know the feeling of being in loss so you will understand what you are really doing.
Newbies should expect a loss, that's so normal
what it should take into consideration is the amount to be burned
however, if the amount is too small, often times those fail trades are forgotten, and if its a big amount it will be remembered
sometimes getting the pain will be the best teacher and experience