Nano/microwires, of semiconducting materials (e.g., GaAs and InP) with triangular cross-sections can be fabricated by "top-down" approaches that combine lithography of high-quality bulk wafers (using either traditional photolithography or phase-shift optical lithography) with anisotropic chemical etching. This method gives good control over the lateral dimensions, lengths, and morphologies of free-standing wires. The behaviors of many different resist layers and etching chemistries are presented. It is shown how wire arrays with highly ordered alignments can be transfer printed onto plastic substrates. This "top-down" approach provides a simple, effective, and versatile way of generating high-quality single-crystalline wires of various compound semiconductors. The resultant wires and wire arrays have potential applications in electronics, optics, optoelectronics, and sensing.