Some embodiments include methods of forming patterns in which a block copolymer-containing composition is formed over a substrate, and is then patterned to form a first mask. The block copolymer of the composition is subsequently induced into forming a repeating pattern within the first mask. Portions of the repeating pattern are then removed to form a second mask from the first mask. The patterning of the block copolymer-containing composition may utilize photolithography. Alternatively, the substrate may have regions which wet differently relative to one another with respect to the block copolymer-containing composition, and the patterning of the first mask may utilize such differences in wetting in forming the first mask.