The energy symbol tell only works on old fakes. New fakes are a lot more advanced.
On new fakes:
the energy symbol is correct.
the accent on the e is present.
the TM on the back of the card is present.
the blue color on the back of the card is correct.
New fakes usually have trouble with numbers. On the HP, weakness, and base attack numbers, the first digit of the number is too far apart from the second digit of the number, and the font is not correct. This is usually visible when you compare the numeral 1 between a fake and real card.
On trainers, the card's name is too bold and the card text "appears" xeroxed.
One of the remaining reliable ways to tell a fake is looking at the font. But new players won't know this. That skill comes after a lot of time of playing or staring at the cards. I end up telling players that the font looks "funny" or "doesn't look right."