> "It's basically compressed cardboard," they told me.

Sometimes literally http://www.refinery29.com/2016/01/101948/ikea-lack-table

Make sure the back is positioned correctly (seated within the recess, and with all corners at right angles), and use twice the number of nails Ikea suggests. This will help maintain rigidity during a move.

If disassembly isn't a requirement, liberally apply wood glue along joints during construction.

Heh, I did that with a 5x5 Billy^W Expedit bookcase in a basement suite... And discovered, when moving out, that it would not fit up the stairs assembled. Hope the next tenant liked it!