Some embodiments include methods of forming plasma-generating microstructures. Aluminum may be anodized to form an aluminum oxide body having a plurality of openings extending therethrough. Conductive liners may be formed within the openings, and circuitry may be formed to control current flow through the conductive liners. The conductive liners form a plurality of hollow cathodes, and the current flow is configured to generate and maintain plasmas within the hollow cathodes. The plasmas within various hollow cathodes, or sets of hollow cathodes, may be independently controlled. Such independently controlled plasmas may be utilized to create a pattern in a display, or on a substrate. In some embodiments, the plasmas may be utilized for plasma-assisted etching and/or plasma-assisted deposition. Some embodiments include constructions and assemblies containing multiple plasma-generating structures.