The assembly process of foldable gift boxes varies depending on their specific designs. Here, I'll provide a general overview of the assembly process for three common foldable gift box designs: tuck-end, hinged-lid, and magnetic closure.

Tuck-End Foldable Gift Box:

1. Lay the flat box on a clean and flat surface, with the printed or decorated side facing down.

2. Fold in the side flaps along the pre-scored fold lines. These flaps will eventually tuck into slots on the opposite side.

3. Fold up the bottom flap along the pre-scored fold line. This flap will become the bottom of the box.

4. Tuck the folded side flaps into the slots on the opposite side, securing the box's structure.

5. Gently fold down the top flaps along the pre-scored lines, closing the box.

6. The tuck-end foldable gift box is now assembled and ready for use.

Hinged-Lid Foldable Gift Box:

1. Lay the flat box on a clean and flat surface, with the printed or decorated side facing down.

2. Fold up the bottom flap along the pre-scored fold line. This flap will become the bottom of the box.

3. Fold in the side flaps along the pre-scored fold lines.

4. Fold the hinged lid along the pre-scored fold line, aligning it with the top edges of the side flaps.

5. Gently tuck the lid's flap into the box's interior, securing the lid in place.

6. The hinged-lid foldable gift box is now assembled and ready for use.

Magnetic Closure Foldable Gift Box:

1. Lay the flat box on a clean and flat surface, with the printed or decorated side facing down.

2. Fold up the bottom flap along the pre-scored fold line. This flap will become the bottom of the box.

3. Fold in the side flaps along the pre-scored fold lines.

4. Fold the hinged lid along the pre-scored fold line, aligning it with the top edges of the side flaps.

5. Depending on the design, attach the magnets to the designated locations on the lid and box walls. Magnets will snap into place to securely close the box.

6. Gently tuck the lid's flap into the box's interior, securing the lid and activating the magnetic closure.

7. The magnetic closure foldable gift box is now assembled and ready for use.