In a small bowl, mix the rice vinegar and sea salt into the warm cooked sushi rice until well combined.
Slice the sashimi-grade salmon, cucumber, and avocado into long, thin strips.
Place one nori sheet on a bamboo rolling mat and spread half of the seasoned rice evenly across the surface, leaving a one-inch border at the top.
Layer half of the salmon, cucumber, and avocado strips horizontally across the center of the rice.
Using the mat, roll the nori tightly over the fillings, lightly wetting the top border with water to seal the roll.
Repeat the process with the second nori sheet, using the cooked shrimp and the remaining cucumber and avocado.
Using a very sharp, wet knife, slice each roll into 8 even pieces.
Serve the fresh rolls immediately with coconut aminos and wasabi paste for dipping.