The expansion by regions is a powerful technique for analyzing the asymptotic behavior of Feynman integrals. The first step in applying this method is to identify all relevant regions. For relatively simple cases involving only Euclidean momenta, it has been shown that the expansion by regions is equivalent to "expansion by subgraphs." However, identifying these regions becomes significantly more challenging under Minkowski kinematics. In this talk, we will explore asymptotic expansions for various massless scattering processes, including both wide-angle and small-angle kinematics. We will review recent progress in the identification of regions and demonstrate how the expansion-by-subgraphs technique can be extended to these scenarios.