A modular universal holding fixture and corresponding methods, accommodating a wide range of workpiece contours, geometries, sizes, and configurations. The fixture may include a fiducial base, a registration frame, and a bridge module. Fixable to a fiducial (reference) location, the fiducial base may be attached in alignment to the registration frame. The bridge module may have a central cavity and guide tracks on top, exterior, and interior support surfaces. The bridge module transversely engages the registration frame for longitudinal movement to a registration position, and supports a tooling for transverse movement. The bridge module may repositionably constrain the tooling at an indexed position. The bridge module may be configured to engage multiple types of tooling and additional tooling headers, supports, and side actuators. A tooling may be passive linear actuators positioned by a N/C operated gantry engaged with the registration frame.