As I used to make popcorn just for myself, in my small but heavy sauce pot, maybe 2 cups?,
I would put a bit of oil to just cover the bottom, heat that, add 3 kernels of corn, cover, wait for them to pop - it's hot enough -
then add enough kernels to cover the bottom of the pan. Hardly shake at all, when the lid starts to lift (LOL, true), count between pops, if you can count to 3/4 without a pop... they are done!
Put popped corn into a bowl, then in the same same hot pan, no heat, add a blob of salted butter, swirl around to melt. Pour over popcorn - grab a cold drink - plop yourself down to watch your movie.
GREAT!