There are two different styles of onigiri: those that are stuffed and those that have seasonings mixed in. For the filled variety, umeboshi (pickled plums), cubes of salt-cured salmon, or tarako (cod roe) are often encased in the warm rice, and then eaten as is or wrapped in nori (dried seaweed). For others, seasonings like toasted black sesame seeds, yukari (red shiso powder), or sakebushi (dried salmon flakes) are simply mixed with the rice and then shaped into the typical triangle, ball, or cylinder shapes. Most importantly, when shaping the rice for onigiri, take care not to compact the rice too firmly. Press until the grains just hold together.