All you have to do is:
-Put some oil in a pot,
-When heated cover the bottom of the pot with your popcorn kernels (not too many, it should be a thin layer),
-Put the lid on,
-Wait until the popping stops/slows down considerably
Season with what you want (do it when the popcorn is still hot so it sticks to the popcorn, you can also season before - when you put the kernels in the pot).
Today I went with sugar and cinnamon!
It tastes just as good as microwaveable popcorn without all the added extras of god knows what that they put in, and I only paid around 1 euro 50 for 500 grams. On the back it says to use 50 grams but as I don't have scales I just guessed. I think it was less than 50 grams and I got so much popcorn!! Whereas buying one portion of microwaveable popcorn is already 1 euro. Cheap, easy and healthy!