In large pot with well-fitting lid and handles, heat 3 Tbl. vegetable oil at med-high for a bit.
Add 1/3 cup popcorn kernels and 3 Tbl. sugar. Stir quickly with wooden spoon and put on lid. Use dish towel to cover top of lid (so any escaping steam and oil won't burn you). Grab handles on each side. Making sure to keep lid on tightly, shake pan back-and-forth quickly. Then heat for a bit more. Then shake vigorously again. Continue to shake and heat until corn starts to pop. As there is sugar in the pan, it will burn if left sitting for very long, so continue to shake vigorously and let sit for a bit. Corn will continue to pop until most of kernels are popped. Remove from heat and carefully open lid. Dump contents into large bowl and immediately salt while still hot.