Potato is not that easy to draw. I think it's rather hard to make it look like potato? Why?
Potato is a stone with lvl 2. Neither thing has got distinctive signs like tomato: juicy red ball with leaves on top of it. Potato is harder, because if You draw a rock, watcher knows it's a rock, but how to change a rock into vegetable?
Potatoes have different sizes, shapes and colours, so they can look differently. All of Your vegetables are good, maybe the second one look like a cheese, but nevermind.
To draw a potato that looks like a potato and the watcher knows it's a potato, I recommend to make background, surroundings to force watcher to think like this. For example, if You place Your potatoes on kitchen table, You know they are not rocks.
Second option is to make a lot of different potatoes and place them together. There is a danger of looking like a pile of stones, but it's not a problem, when You'd make really really different potatos.
I know this is making things the wrong way, but I wanted to say something about potatoes, because they're awesome.
And here's my potato. He's named Fred.
