B meson decays are important players in the search for physics beyond the Standard Model (SM) of particle physics. In this search, one of the key points is understanding the mechanism of CP violation. In flavour physics, the large amount of data gathered by the B factories and LHCb probe the SM with an unprecedented precision, probing scales much higher than the LHC. Naturally, this also requires precise theoretical predictions. In this talk, I will present some of the challenges and new ideas to push the theoretical precision up. Specifically, I will focus on the deterination of the CKM element Vcb and non-leptonic decays.