The basics of packaging design. Again, grounded in graphic design. Just imagine going to the supermarket and you see two different sodas or even going into the wine store and you see two different types of wine and one label looks better than the other. What made you pick it up? This is what a lot of designers think about in terms of packaging design and what's going to make the consumer see that this is different or what makes the want to pick it up. What is going to be best express what is actually being packaged. It has a lot to do with no only knowing the dimensions of your product but also knowing your target audience, where the shelf space is going to be, to know how to design for that. If its going to take up to much shelf space, which is actually very costly for the company. There's a lot of different variables and factors that go in package and design.
One of the best sites that I pull from is thedieline.com. they have been out for about four or five years. They round up the best packaging design all over the world from big corporations all the way down to student competitions. I went to Creative Circus and there was a lot of people from my school whose package designs got featured on the site. If you want to be in package design, you have to know materials. You have to know the different ways of manufacturing. You have to know the color process, C-N-Y-K, being able to know the pan tone colors and know how to make sure that your product is actually printed the right way.
Packaging design is actually a beast of itself. It is one of those things that if you want to do it you should focus solely on that. However, there's so many good resources out there and so many different communities to get excited about.