From paper to project
Identify the outer perimeter and internal lines first.
Cut only the solid outline.
Place a ruler on each fold and score lightly with a blunt tool.
Pre-fold without glue to check the fit.
Place tabs on the inside and work out which surfaces join.
Glue one join at a time and wait before forcing the next side.
Check it with an example
For the cube box, cut its perimeter and notches, not the boundaries between the six squares. Keep the tabs to join them.
If it does not turn out as expected
Do not score with a knife. A missing tab can be repaired with an internal paper strip on a decorative box; that does not make it suitable for heavier loads.
