To get better layer adhesion, lions print hard TPU, HT-PLA, PETG with the nozzle at 260C.  To further improve layer adhesion, there's no print cooling.  Basic PLA seems to max out at 220C before it clogs.  The trick with 260C is the Ender 3 can't reach it unless the airflow is blocked below the heat sink with a piece of cardboard.  

Then to manetain the heat break, you have to blow colder air at the unblocked part of the heat sink.  Lions do this with a cardboard air scoop to pull air from away from the bed heater.  

Even then, the nozzle clogs if the ambient temperature is over 90F.

The thermocouple also tends to glitch during the start of the print.  Wiggling the wires & restarting the print usually stabilizes the thermocouple.  For expensive filament, it's better to start the print without filament, let it print air for a while, then restart with filament.

The thermocouple glitches are believed to be caused by bad contact with the aluminum.  Removing & reinstalling the thermocouple sometimes improves it.  Some heating problems are caused by the ceramic element not fully contacting the aluminum.  Its set screw has to be tightened.