Sushi rolls keep getting thin
I have a couple of suggestions, which have helped me.  First, cut your nori a bit larger.  Rather than using a half sheet, go for two-thirds a sheet.  Of course this will produce a smaller portion, for which you will need to devise a creative use (I've used them for hand rolls), but beginning with a larger sheet leaves you more room for error as you are learning to create consistent rolls.  Second, I like to try to create a layer of rice that is one grain of rice thick.  Of course, it doesn't always happen this way, but it allows me to work at keeping the rice layer uniform. Forget the &quot;lemon-sized ball.&quot;  Just make a layer of rice, always leaving some exposed nori along the long edges so you can create a seal when you roll. Use a bowl of water to keep your hands moist, and avoid sticking rice. It does take some practice, so keep at it.  Once you are producing consistent results, you can go back to a half sheet.