Your phone should come at least 40% out of the box ,but there are no wrong or right ways cause the lithium ion has no memory as the old gadgets(remember camcorders) then our early phones and the whole battery fire problem has been more than rectified except on Tesla models lol. But I never experienced or my friends had that issue with Samsung products and I'm usually mother goose when people follow my lead.But use only the charger provided that's made for your gadget. I'm sure the original Tesla (the inventor of AC CURRENT) I'm sure agrees if you care to read all those little # s on your charger cause they mean a lot and keep us safe and ultimately just charge as needed cause there are no bonuses when charging different ways especially on Samsung anything
On average after fill charge, always charge to 80% You will extend your life span of the battery to 200%. It only cost 0.26 cycles in wear. Every time your phone goes through a charging cycle, your battery wears out. Try Accubattery to monitor your battery. Also, charge your phone when it goes down to 20% not 0%. As for reasons stated above.
Everyday I make sure my device is almost dead before time to go to sleep so then I can not worry for it to be plugged in when it's at %60
But mines at 28% so wont I go to bed then that's when I charge my phone