Puzzle-box gift cube

This is a gift box of sorts, made of six identical parts that go together in a somewhat puzzling manner. There are three styles, each held together by a combination of tabs and/or slots.

Boxy #1 - Each part has two projecting tabs and two slots; the box is held together by arranging the parts so two tabs on each side lock into the slots of two adjacent sides while two other slides lock into this side's slots. This version works requires material with a balance of flexibility and rigidity.