I would probably start out with a primitive cylinder, add some height segments. Drag in a taper deformer, adjust it until the shape suits your liking. Make a copy of the the deformed cylinder, hide it. select the visible cylinder press "c" to make it editable. Make a loop selection of the cylinder's top, press delete. Select the cylinder's side walls, bevel them out a little to give the object some depth.
At this point you should have the basic shape of the yogurt container. You might want to add a lid and start texturing. Its likely you will need to do some custom uvw mapping to get the branding graphics to wrap the container. There are a ton of tutorials that can walk you through this part.