Each project will require a different technique and style depending on the designer requirement and the client criteria but it would likely start off with this three simple step...
Let’s start off with your Sketchup model shall we? (25-30% in)
My process simply start off by taking your Sketchup model and determent if It need to be tweak or add anything to help complete the whole picture. In could cleaning it to get to the workable size.
This step will require some amount of preparations to the model to get it ready for the next step including choosing the right view angle and also the right materials and entourage.
I offered used some basic plugin for Sketchup to improve the rendering results.
Adding my line works and layering everything in Photoshop... (additional 15-20% )
After we have all the components we need then I’ll bring them in to sketchup and layering them accordingly.
In some cases, I even draw the line works by hand to give a little more personal touch and character to it.
Let's make the magic happens! (remaining 55%)
This step require a lot of personal touch and aesthetic sense from illustrator to help designer and the client visualize the space and to give them a better understanding of it functions also of the people who will be using it.
Using Photoshop is fun! The more time you spend, the better it get but in most cases time is the luxury our client can not afford.
believe me when I said, experience and keen observation skill help speed up this process immensely, therefore we can spend more time toward perfection!