Methods of forming an optical element, and related devices, components, and systems are disclosed. One method comprises printing a mold element comprising at least one mold surface using an additive manufactured device. The method further comprises providing a plastic sheet over the mold element. The method further comprises vacuum thermoforming the plastic sheet such that at least a first portion of the plastic sheet conforms to the at least one mold surface of the mold element. This vacuum thermoforming of the plastic sheet forms an optical element from at least a second portion of the plastic sheet. One advantage of this method is that different optical elements may be quickly and inexpensively fabricated, thereby reducing the cost of development and production of the optical elements.