Iron-based superconductors represent a second class of high-temperature superconductors after the copper oxides. As they enter their second decade, the large variety of their chemical structures, modes of magnetic ordering and the methods available to tune their properties are all the more appreciated. As with many unconventional superconductors, their magnetic order needs to be suppressed for superconductivity to appear. I will present an overview of the magnetism in several of these iron-based materials and the methods to suppress, or tune, it. Magnetism is particularly strongly coupled to the crystal lattice, which makes structural tuning parameters interesting. I will also discuss some of the other surprising effects that arise from this close interaction of structure, magnetism and superconductivity. Comparing diverse materials and their properties helps us understand some of the common principles within this class of unconventional superconductors.