The practical application of MCRG requires the flow lines to reach the renormalized trajectory after a small number of blocking steps. It is suggested to use optimized block transformations in order to shift the fixed point and the renormalized trajectory closer to a given action. In asymptotically free theories, perturbation theory can be used to find the improved block transformations. Another MCRG method, the improved ratio method, is discussed also. The methods are tested on d=2, asymptotically free spin models.