Pro-tip I only realized later when making much bigger ones: it's worth to pay attention to the "grain", that is the orientation of the corrugations.

Find it hard to describe, but they should go "perpendicular to the axis of load". E.g. if you have an upright wall the top and bottom edge should show the "waves"; your base (and top) plate should have the "waves" showing on the left and right edges.

Took me some time to get used to thinking about it and it makes cutting out individual pieces (a lot) more involved, but the payoff is real for big units (big as in 50 x 30 x 40 cm; no longer can you move it one-handed!).