Cook your rice in a rice cooker according to the package.
Once the rice is cooked, set it aside for about 10 minutes in a new bowl. Add your seasoned rice vinegar and mix. Set your rice aside until completely cooled.
Once your rice has cooled you want to add a thin layer of it to your nori sheet. Be sure to leave about 1 cm of nori without rice on it, on the top and bottom, this helps for when you have to roll it up. It helps to have a bowl of cold water next to your work space as the rice can be very sticky. Keeping your hands wet will help control the rice better.
Layer your sliced vegetables of choice about halfway down your rice. You can use any variety of vegetables you prepared.
Dampen your exposed nori, this will help keep everything together. Using both hands gently roll your sushi, ensuring that all your filling stays in. It is kind of like rolling a burrito, you tuck and roll. When it is completely rolled up, be sure to give your roll a good squeeze with the mat to ensure that they are together. Add more water to the seem if needed.
To slice your sushi make sure you are using a very sharp knife. If you wet it, it will also help you slice through your roll.