If the fracture plane is oblique and long enough, they may often be fixed satisfactorily with lag screws after reduction. Screws must have adequate purchase in the lateral cortex to provide stable fixation.
Disimpaction is the key to successful reduction.
After reduction, alignment should be correct in both sagittal and coronal planes. Rotational alignment must also be correct.
Choose whichever approach is best suited for anticipated reduction maneuvers. The deltopectoral approach, while more extensile, is more invasive.