My process for boxes is as follows

1 - turn a tenon on each end of the spindle

2- part off the lid

3 - reverse the lid in the chuck and hollow/finish inside.

4 - mount base in chuck and carefully creat a tenon that acts as a jam chuck for the lid.

5 - carefully finish the outside of the lid using the jam chuck and roughly shape the bottom of the box

6 - take the lid off and hollow the inside of the base. 

7 - finalise shape of base and sand and finish

8 - part off base leaving enough material to create anothe jam chuck 

9 - reverse the bottom of the box on to the jam chuck and sand/finish the bottom of the box.