Here is an example of my design process:

I've recently returned from a trip to Northern Scotland.  I shot this image - a textured glass window of one of our B+B's.  I just liked the texture and initial design:

I opened the file in Photoshop and started working with the image - here is the initial design for a 40" x 80" wrap:

Then I started using various tools to see how other color combinations worked:

The next step in the process would be to choose which colors actually go to print.  Oftentimes I'll print these out on paper to see what resonates with me. Or, I'll look at the collection in the making and see what colors would compliment the rest of the collection. Do you have a favorite?  let me know!

Additionally, I'll take the design and see if it works in another size format - ie, changing an oblong into a square and vice versa.  Here's this design as a square:

So there you have it - from beginning image capture to design!