As I was working last night, I thought I could post part of the design steps I follow as I create a pattern. The process varies a little bit with each design, but pretty much this is the way I work.

I had already drawn a sketch on a piece of paper. Once in Illustrator, I draw the outlines of the main characters.

Then I draw the outlines of other design elements. I usually start my designs in black and white, then choose a color palette.

I add fill color and patterns, also details to the drawings.

Then I repeat the motives all over the canvas, flip a few, change colors in other. I also added an extra layer in the background to tie it all together.

Make sure it looks well placed on the canvas and clean the borders.
Of course a while after I'm done, when I look at it again, I find several things I want to change, and in many cases, I do change them. My husband says my staple phrase is "it's not finished". Pretty much his comment to me goes like this: "oh I like what you did, it looks good, nice job honey... I know, I know... it's not finished".