You will need:
A plastic container
Something strong enough to cut the top off your container
Sandpaper or sanding block
I show the original container, label removed.
Next we have it sanded. I sanded both horizontally and vertically to give the gesso a nice texture to stick to.
Remove the top, sand the edges.
Two layers of gesso.
First layer of paint, a base layer that will get covered by other colors later.
...and a finished vase. It could also, obviously, be sealed.