Acutally your texturing isnt far off the originals. i just googled imaged them and the only big difference is the amount of detail in the modeling. For example His nose is more bulbus in Toy Story, he has laces on his shoes, they both have eye lids and eye brows. Mrs Potato head even has eye lashes.
I think the next step is for you to learn to add more detail in your modeling as everything ive seen you do seems to be pretty much a primative object with slight deformations.
I am also asuming you dont have photoshop or some form of photo editing software... This makes doing detailed textures pretty hard so you will have to stick to the procedural textures.
If you need some inspiration why not try modeling some toys like a lego man or pogo stick, stuff that you have around or can find good references on. in fact a lego man would be an awsome one but try and get it as accurate as possible.
Remember there is the video training on the site too that cover lots of usful stuff and everyone on here will be willing to help too.