Guideline #1. Avoid meaningless, extra design elements that needlessly burden cognitive load.
In a study by Google, researchers found that not only will users judge websites as beautiful or not within 1/50th – 1/20th of a second, but also that “visually complex” websites are consistently rated as less beautiful than their simpler counterparts.
Moreover, “highly prototypical” sites – those with layouts commonly associated with sites of it’s category – with simple visual design were rated as the most beautiful across the board. In other words, the simpler the design, the better. Your ecommerce homepage design process should leverage this information.
The reason less “visually complex” websites are considered more beautiful is partly because low complexity websites don’t require the eyes and brain to physically work as hard to decode, store, and process the information.
The more color and light variations on the page (visual complexity), the more effort required for the eye to send information to the brain. This is why it’s important to remember that every element –typography, logo, color selection, etc.– communicates subtle information about a brand.
When these elements don’t do their job, the webmaster often compensates by adding unnecessary copy and/or images, increasing visual complexity and detracting from the overall aesthetic.
Optimizing a page for visual information processing –minimizing the amount of information traveling from eye to brain – is about communicating as much as you can with as few elements as possible.
Learn more from our study on homepage layout and value proposition.
How NOT to do it
Forever 21
This homepage incorporates several moving graphics, bright colors, and an auto-rotating carousel.

TigerDirect
This incredibly busy homepage could stand to lose quite a few design elements (logos, graphics repeated across the page, text elements, etc.).

The main page was slightly busy. It seemed to put more emphasis on, "Hey! Look at all the stuff we have!" rather than helping the user navigate to what type of items they may want to purchase.
User quote on TigerDirect
How to do it RIGHT
Home Depot
This homepage follows prototypicality, uses lots of

I like that the pictures of the products were big, and it looks very clean.
User quote on Home Depot
Petsmart
This simple homepage has a clear visual hierarchy and follows conventional design.

I like how everything was laid out and you didn't have to go around guessing where things were.
User quote on PetSmart