Nooblet Cola.

[Ornust]

I honestly don't know what I was thinking when I left the white Background there, but I don't know how to shade this, either. 

[Blick]

Well, giving it a try would be a start.

[Ornust]

I did, but it didn't work out as I'd like.

[bengo]

Well, I'm not doing it for you, here's some good tutorials:
http://derekyu.com/extras/pixel01.html
http://www.natomic.com/hosted/marks/mpat/
http://www.spriteart.com/tutorials/02_ambient_sphere.html
Learn how to do it yourself, instead of us spoon feeding you, I'm only giving you tough love because I care.

Edit: Here's a good reference of coke cans: http://images.businessweek.com/ss/06/06/failures/image/coke.jpg

[ceddo]

I did, but it didn't work out as I'd like.

Posting your attempt would be a good idea. That way we can at least tell you what you did wrong, and help you make it work out. It's what WIP threads are for, actually.

[Ornust]

Well, I'm not doing it for you, here's some good tutorials:
http://derekyu.com/extras/pixel01.html
http://www.natomic.com/hosted/marks/mpat/
http://www.spriteart.com/tutorials/02_ambient_sphere.html
Learn how to do it yourself, instead of us spoon feeding you, I'm only giving you tough love because I care.

Edit: Here's a good reference of coke cans: http://images.businessweek.com/ss/06/06/failures/image/coke.jpg

I'm not asking you guys to do anything for me, but I am asking for Criticism. Not only that, I've looked at all those tutorials and much more. (Including every single one in the, er, Stuffz thread!)

Oh, here:

[AdamAtomic]

Ornust, if you present something that is not shaded, and you ask us to critique your shading, then all we can say is "probably it needs shading."  50-50 dither up the side of your line art does not constitute shading either, before you ask.  Shading (or conversely lighting) a form is a very complex process that requires thought and planning!  Here is a good tutorial that explains the basics of light and shadow in clear and simple terms:

http://www.itchstudios.com/psg/art_tut.htm

Note that it is NOT a pixel art tutorial.  That is because the problems you are having with your artwork are not related to pixel art at all.  Pixel art is just some specialized techniques that build on a full foundation of artistic skills.  Try sketching or painting a few cylinders with a semi-realistic light source, and then take a crack at pixeling it onto your can.  Then post that image back to this thread so that you can give you some pointers!

[Ornust]

I have looked at that tutorial a few times already, but I shall read a fourth time, I suppose. (I can never remember ANY of it.) 

[Blick]

You don't have to read the entire thing and take everything from it in mind. Just find the parts that are relevant. I'd say the images are the most important part in it. Understand them.

Also, references are helpful more often than not. You may want to check the shape of the top of your can, by the way, it's out of perspective with the rest and the sides curve a bit too much at the top compared to all other cans I've seen.

[Ornust]

Gee, I just read through the whole thing again, and I've forgotten everything I've read. Except perhaps Ambience and Radiosity.