Prepare a dipping water-vinegar solution to dip your hand with while working to prevent sticking. Use a 1:4 ratio (1 Tbsp rice vinegar to 4 Tbsp water).
Cook, season and prepare sushi rice, if you need more instruction, take a look at the guide on cooking sushi rice. We need about 1/2 cup cooked sushi rice for every roll.
Prepare the work area, preferably leaving your bamboo mat on a flat surface like counter or cutting board. Have plastic wrap available if you want to invert the roll.
Cut sashimi in to 1/2 x 1/2 x 4 inches sticks.
Fold a piece of nori in half, carefully tear along the folding line.
Lay the half nori on top of bamboo mat over a flat surface.
Spread 1/2 cup of seasoned sushi rice over nori leaving about 1/2 to 1 inch empty on the farther end.
Now arrange a fish stick or any other topping on top.
Carefully lift, tuck and roll. Apply pressure over bamboo mat a few time to hold the roll into shape.
Repeat for other hosomaki rolls.
Use a sharp knife to cut. You might need some damp cloth to wipe the knife off in between..
Enjoy as is or serve with pickle ginger and some hot wasabi.