I was not sure whether writing a comment or a critic but you requested for a critic and I thought it'd be fair to give one even though this tecnique is not quite close to what I do in art, I guess I will give you my critic from the costumer's point of view.

I obviously love your designs because they are very you, I mean you input your personality and your style in everything you do and that makes it so your own, but I guess I'll speak about the colors, am not sure if the shoes were that dark base color at first or if you painted it, but I think that the dark background makes the whole image lose itself, I think that you should have tried to use more contrasted colors that helped you stand out the first image from the background, so that it would look a little more full of live, what I mean is that maybe a lighter background paint or shoe base would have helped to appreciate much more the design of the shoe itself, although I love the design I think that the shoe color just doesn't make it for me.

but Hey you are an amazing artist am just talking from a viewer's eyes *hugs*

I am new to this critique thingymobob aswell, but it seems pretty cool, a very good idea! There are rating options at the side...

I love these definately all 5*

You should give the butterflys some shadows that would look really cool!

I believe this gets sent to you for review first, delete it if you wish I was just curious

...Ahh.. so a critique has to be at lease 100 words for it to be posted, that makes sense! Otherwise it would just be a comment lol. And Im just writing this in to make it to 100 haha!