In recent years, noniterative Correlation-based Tuning (CbT) and Virtual Reference Feedback Tuning (VRFT) have been proposed as an alternative to the standard model-based approach for model-reference control design. In this work, the problem of input design for direct data-driven controller tuning methods is investigated. For bounded input energy, the excitation signal is designed such that the bias on the expectation of the control criterion is reduced. The above strategy is numerically tested on a benchmark example.