Nose gear failure in single prop aircraft: belly landing or nose landing?
The standard procedure is whatever is in the POH for your aircraft. This is from a C182RG POH:


  LANDING WITH A DEFECTIVE NOSE GEAR (Or Flat Nose Tire)
  
  
  Movable Load -- TRANSFER to baggage area.
  Passenger -- MOVE to rear seat.
  Before Landing Checklist -- COMPLETE.
  Runway -- HARD SURFACE or SMOOTH SOD
  Wing Flaps -- 40°
  Cabin Doors -- UNLATCH PRIOR TO TOUCHDOWN.
  Avionics Power and Master Switches -- OFF when landing is assured.
  Land -- SLIGHTLY TAIL LOW.
  Mixture -- IDLE CUT-OFF.
  Ignition Switch -- OFF.
  Fuel Selector Valve -- OFF.
  Elevator Control -- HOLD NOSE OFF GROUND as long as possible.
  Airplane -- EVACUATE as soon as it stops.
  


That assumes that you've already run the gear extension failure checklist without success, of course.