Multimode optical fibers have seen increasing applications in telecommunication, imaging, spectroscopy, high-power lasers and amplifiers. However, inherent imperfections and environmental perturbations cause random mode and polarization mixing in the fiber, resulting distortions of optical signals in space, time and polarization. These distortions pose serious issues for communication and imaging applications. In this talk, I will present our works that not only correct the distortions induced by random mode mixing, but also utilize strong mode coupling to enhance the coherent control of light propagation in the multimode fiber. We show that by tailoring the input spatial profile of coherent waves, a strongly broadened and distorted pulse transmitted through a multimode fiber can be compressed, increasing the bandwidth of the system. Besides the temporal shape, we also demonstrate an effective control of the polarization states by shaping the input spatial profile.