Design is Iterative.
My design process is a continuous loop of researching, designing, and testing. Something about every design can always be improved, it's not an exact science. I find that my process focuses a little more on need-based design and testing prototypes, but recently, as my knowledge of visual design has grown, I have begun to enter visual aspects of design into my process as well.
After researching, I create low fidelity paper prototypes, this often comes in the forms of a dozen to thirty different sketches of layouts for a particular site design.
Paper prototyping creates a unique way to do low fidelity testing. By sliding the papers through a makeshift phone, tablet, or laptop screen, I can test the general layout before designing in the computer.
Organizing the data that goes into the prototype is important to the process and information architecture helps separate it into categories that makes sense.
Transparent paper prototyping helps to find layouts among information, once an information architecture is set up and we know what needs to go where, we can learn to place different parts in a visual order and layout that makes sense.
I have found that pin-up critiques really help with both getting feedback from other people, as well as viewing your systems visually as a whole, and making sure that branding fits in with research.
This entire process gets cycled through multiple times within one project and may happen in different orders. The idea is that the system is never ending and continues to update with changes in interface design.