Thanks a lot, I thought you would just move the pivot, THEN switch to rotate tool, and that the pivot would stay on its place. Your method worked flawlessly,

Here is an update:



I drew the mesh keeping overlap in account, so just like with the real carton. (folding edges not exactly aligned). So I guess the next step is extruding inwards, I'll see how far I get, but don't hesitate to post the instructions anyway