Rinse the sushi rice under cold water until the water runs clear.
In a rice cooker, combine the rinsed rice and water, then cook according to the manufacturer's instructions.
Let the rice rest for 10 minutes, covered.
Transfer the rice to a large bowl and sprinkle with salt, mixing gently.
Wet your hands to prevent sticking and take a handful of warm rice.
Create a small indentation in the center of the rice.
Place your chosen filling into the indentation.
Mold the rice around the filling, forming a triangular shape.
Wrap a strip of nori around the bottom of the onigiri.
Optionally, sprinkle sesame seeds on top for added flavor.