Abstract. We present the detailed analysis of a new two-pulse orientation scheme that achieves macroscopic field-free orientation at the high particle densities required for attosecond and high-harmonic spectroscopies [P. M. Kraus et al., arxiv:1311.3923]. Carbon monoxide (CO) molecules are oriented by combining a one-color and a delayed two-color non-resonant femtosecond laser pulses. High-harmonic generation is used to probe the oriented wave-packet dynamics and reveals that a very high degree of orientation (N up /N total = 0.82) is achieved. We further extend this approach to orienting carbonyl sulfide (OCS) molecules. We show that the present two-pulse scheme selectively enhances orientation created by the hyperpolarizability interaction whereas the ionization-depletion mechanism plays no role. We further control and optimize orientation through the delay between the one-and two-color pump pulses. Finally, we demonstrate a complementary encoding of electronic structure features, such as shape resonances, in the even-and odd-harmonic spectrum. The achieved progress makes two-pulse field-free orientation an attractive tool for a broad class of time-resolved measurements.