Help me fix my veggies!

[Chutzpar]

You haven't fixed your lines at all!

Beyond jaggy lines, the most fundamental flaw I'm seeing with these is that it doesn't seem you're thinking of the characters as 3d forms. The reason the carrot looks better without shading is because the shading was completely ruining the illusion of the carrot as a cylindrical... thing.

I whipped up a quick drawing for you:
The top is what you've done, the bottom is my (very sloppy) sketch showing you what you need to keep in mind.
The curves I've drawn on the surface of my fix might not make sense to you; what I did was "draw through" the form, so you can see part of the line on the opposite side, too.