It is often the case that our ability to find evidence for new physics is bounded by our control of theoretical uncertainties. Of particular importance are those uncertainties which arise due to QCD corrections which mask the underlying short distance (new) physics of interest. Effective field theories have proven invaluable in controlling these uncertainties. However, canonical effective field theories are often insufficient in cases where experimental cuts, necessary to remove backgrounds, force theory into corners of phase space. In such, cases we must design an effective field theory which is particular to the case under study. In this talk I will discuss two scenarios where designer effective field theories are necessary: The extraction of the CKM angle from inclusive B decays, and the production of top quarks at threshold.