In agreement to the said above, I've been taught to check speedbrakes retracted, select flaps up, start APU... only after the runway had been vacated, taxi instructions received from ground control, apron map consulted, situation briefed to the captain, first/next intersection located and agreed upon by both crewmembers, and right side clear check performed. Only then head down. The very and only exception (non-SOP) is that I select the timer on at 60 kts to calculate landing time once parked and I may elect to stow flaps on RWY below 60 if the turnoff is far enough ahead. How do I tell? Once the capt. closed reversers and retracted the speedbrakes thus disarming the autobrakes...
Works safely me thinks.
Cheers, FD.