Turing systems have been invoked to explain examples of pattern formation in development. On the one hand, spontaneous pattern formation in Turing systems relies on feedback to amplify the developing pattern. However, in cells and tissues patterns generally do not form spontaneously, but are under control of upstream pathways that provide molecular guiding cues. The relationship between guiding cues and feedback amplification in controlled biological pattern formation remains unclear. On the other hand, the feedback structures that enable pattern formation can rely on an intertwined coupling between mechanical events such as force generation and flows, and regulation. The physical basis that underlies such types of pattern formation are not well understood. In this talk I will report on our recent findings on how the C. elegans zygote undergoes polarization, and on how the red flour beetle Tribolium castaneum undergoes gastrulation. In both cases I will highlight the role of force generation and flows, how such mechanical processes contribute to pattern formation. I will also discuss how such modules of mechanochemical feedback are guided by external and upstream cues, to achieve the appropriate structure at the right place and the right time.