Methods of forming at least a portion of an earth-boring tool include providing at least one insert in a mold cavity, providing particulate matter in the mold cavity, melting a metal and a hard material to form a molten composition, and casting the molten composition. Other methods include coating at least one surface of a mold cavity with a coating material having a composition differing from a composition of the mold, melting a metal and a hard material to form a molten composition, and casting the molten composition. Articles comprising at least a portion of an earth-boring tool include at least one insert and a solidified eutectic or near-eutectic composition including a metal phase and a hard material phase. Other articles include a solidified eutectic or near-eutectic composition including a metal phase, a hard material phase and a coating material in contact with the solidified eutectic or near-eutectic composition.