Expert bakers: How do I stack a 4 layer cake so that it's not lopsided?

[janet bubby]

It does look great. Definitely pick up a leveler, I try to freeze my layers before levelling / assembling as well.

[gentlearts]

I just want to add that I don't know what a leveler is, but if it is a tool for cutting even layers, all you need is a few toothpicks.
Stick one in the side of each quadrant of the layer. Place a second toothpick next to one of them, and use it as a guide for your serrated knife.
When you put it together. Use the double toothpick to match the layers to the same spot.