Methods of forming magnetic memory cells are disclosed. Magnetic and non-magnetic materials are formed into a primal precursor structure in an initial stress state of essentially no strain, compressive strain, or tensile strain. A stress-compensating material, e.g., a non-sacrificial, conductive material, is formed to be disposed on the primal precursor structure to form a stress-compensated precursor structure in a net beneficial stress state. Thereafter, the stress-compensated precursor structure may be patterned to form a cell core of a memory cell. The net beneficial stress state of the stress-compensated precursor structure lends to formation of one or more magnetic regions, in the cell core, exhibiting a vertical magnetic orientation without deteriorating a magnetic strength of the one or more magnetic regions. Also disclosed are memory cells, memory cell structures, semiconductor device structures, and spin torque transfer magnetic random access memory (STT-MRAM) systems.