Two new stability design methods are demonstrated and validated: the Overall Strength Reduction Method (OSRM) and the Overall Imperfection Method (OIM). Both methods are based on the linear buckling analysis (LBA) of global structural models and use the standard reduction curves. The OSRM is formulated in the classic way using generalized slenderness and reduction factors while the OIM uses equivalent amplitude for the buckling mode based geometrical imperfection. These new design methods cover all types of buckling modes, which can be calculated by LBA of structural models composed of tapered members with arbitrary support conditions and subjected to any complex loading. This paper clarifies the mechanical interpretation and proper calculation of all the components of the two methods in case of tapered members with arbitrary support conditions. The validation is performed on GMNIA results for several different buckling situations of tapered members proving the accuracy of the OSDM.