Magnetic domain observation and prediction have been the subject of continuous scientific interest for over a hundred years. The characteristics of magnetization patterns are notoriously difficult to elucidate, since they intricately depend on the balance of multiple interactions present in magnetic systems. A particular challenge comes from the fact that magnetic systems fall into the category of systems with competing short-range and long-range interactions. We will introduce the subject of magnetic stripe patterns by showing various observations in thin magnetic films of thicknesses varying from a single atomic layer to millimeter thick layers, and presenting the state of the art in magnetic stripe modeling. In the second part we will introduce in details our recent results, where a reduced 2D micromagnetic model was used to obtain asymptotically exact formulas for the stripe equilibrium width in ultrathin films and multilayers. Finally, we will show how micromagnetic simulations can be used to numerically validate the regime of applicability of different models and obtain the equilibrium stripe width in the regime where no analytical model applies. As a perspective to our work, we will discuss the transition from the 2D to the 3D case.