Mystery in a Corner and Frogging

This first photo shows my MIAC "almost" done. I decided to add my own border and thought I would use basketweave. It is nice and relaxing, right? Well, after stitching for several nights, I noticed that the blue DMC I was using had changed shades. Not a lot, mind you, but I could see it. I decided to sleep on it and wait to take it out. I knew I was not going to have enough thread anyway and needed to get more. But the more I thought about it, the more I knew it needed to go. One reason was the color change. I would always look at the piece and KNOW. And the basketweave was taking forever! I need a different stitch!

When I went to the store, I saw a lighter shade of the blue DMC that I had been using. (The dark is 517 and the light is 519) The lavender I used looks ok, but I was never totally happy with it so I bought several skeins with the idea to do more ripping. Here is the result:

I haven't ripped all the lavender out, but I will. The light blue looks so much better! I am much happier with the piece now. Here is the part of the center that I redid:

So, does anyone have any suggestions for a border? I am thinking about a diagonal byzantine, but I am not sure. How do designers do it? This is a lot of work, but I am enjoying it and learning a lot.