Impressing a girl a few weeks prior to smashing her box. Preparatory work can include assisting her with something (i.e moving apartment), lending her books/DVD's or simply talking to her. Note: Doing the 'Spade Work' is different to 'chatting a girl up' (see: chatting up)because it is the continued premeditated effort with no return on investment expected for a number of days or possibly weeks.
Preparatory work necessary for a project or an activity.
Jonathan: "Morning Hubert, I saw you talking to Deborah earlier, it appears she is becoming increasingly comfortable around you by the day. Some mighty fine Spade Work if I do say so myself"
Hubert: "Your observations are correct Jonathan, I'm hoping Deborah lets me smash her box within the month."
(see: Smash Box)