1. Rinse the sushi rice under cold water until the water runs clear.
2. Cook the rice in a rice cooker with 2.5 cups of water.
3. In a small saucepan, combine rice vinegar, sugar, and salt. Heat until the sugar dissolves. Let it cool.
4. Once the rice is cooked, transfer it to a large bowl. Pour the vinegar mixture over the rice and mix gently. Let it cool to room temperature.
5. Place a sheet of nori on the bamboo mat. Spread an even layer of rice over the nori, leaving a 1-inch border at the top.
6. Arrange cucumber, avocado, and salmon strips along the bottom edge of the rice.
7. Roll the bamboo mat away from you, pressing gently to shape the roll. Seal the edge with a little water.
8. Use a sharp knife to slice the roll into pieces. Serve with soy sauce, pickled ginger, and wasabi.