Abstract: Identifying the optimal quantum metrological protocols in presence of realistic noise may be challenging. Brute force methods usually do not allow to study models in the regimes interesting from practical point of view. In this talk I will present the state-of-the-art (and even a bit beyond..) tools that allow for an efficient search of the optimal protocols even in asymptotic regime of infinite available resources (particles, time, etc..) as well as methods to derive fundamental bounds that can certify their optimality.