THE COMMERCIAL-RATED PILOT WAS RECEIVING INSTRUCTION & TRAINING FROM A CFI IN PREPARATION FOR A BFR. DURING A LOW LEVEL APPROACH TO A PRIVATE STRIP, THE LEFT WING DIPPED AND STRUCK TREES AT THE APPROACH END OF THE AIRSTRIP. THE AIRPLANE VEERED LEFT, CRASHED NOSE DOWN, LEFT WING LOW AND RECEIVED SUBSTANTIAL DAMAGE. THE CFI REPORTED THAT THE AIRCRAFT WAS ON GLIDE PATH, '... BUT A LITTLE LEFT OF CENTERLINE ... (PILOT) WAS CORRECTING SO (I) DIDN'T SAY ANYTHING.'