Pulling off the bottom plate once you've removed the screws. It's not essential, but it obviates the risk of damaging the case with a spudger or other prying tool.

I always lifted it up from the heatsink side with my fingers. It overhangs a few mm from the hinge.

I think it's not possible to open 2016+ models without suction cup anymore, there is some weird clips inside that open up with bending of of case.

I think Apple finally won with making their computers impossible to open.