When making my sushi rice, instead of using rice vinegar and sugar I substituted for kombucha tea instead.
Instead of buying “Japanese sushi mayo” I mixed plain balkan style (thick) unsweetened yogurt with a dash of kombucha tea and wasabi powder and spread the mixture on the inside of my sheet of nori. Then spreading the sushi rice on top (if you want the nori on the outside when rolled, or spread the yoghurt mayo on the opposite side of the nori after you have flipped the rice side over if you are rolling the rice so that it is on the outside.
When I cooked my rice, I added slices of peeled yam to cook with it, to be later added as part of my roll filling.
I also added julienne slices of peeled cucumber and extra firm tofu as part of my roll filling instead of crab sticks.
Once the filling was layer out on my sheet of nori I sprinkled some dried fish flakes and toasted black sesame seeds before rolling it. You can roll the rice inside the nori or on the outside.