I recently chatted with LEGO about their customer experience efforts; they've got a lot of interesting initiatives underway. One of the things that really caught my eye was a tool they call the "experience wheel."
Create consistent color schemes With Colllor it is much easier to generate a consistent color palette with just a few clicks. You should use colors consistently, so you have a common look and feel throughout your design. All the alternative proposals produced by Colllor derive from the same color and they all have a common denominator sharing hue, lightness or saturation values.
We visited a bit of IDEO where they invent toys, and they told us about products. Products they told us have to be "shelf demonstrable" (an alternate term I heard later is "shelf evident" which you have to say like Sean Connery saying "self evident"). This is the idea that regardless of what your toy - your product - does, you have 15 seconds for it to tell its story to the customer, before they even touch it. This doesn't need to be every feature of the product, and it doesn't even need to be accurate. But in 15 seconds, you need to communicate that combination of usefulness and desire that makes a potential customer walk to the shelf, pick up the product, handle it, and put it in their basket.