I think I've finally reached the end of things to say about this sweater ... haha!
First, I want to marvel at the fact that I had this amazing wooden button in my stash.  It matches the mid-purple perfectly.  I still can't get over that.

I originally had the button closure lower on the sweater, but after wearing it a couple of times, I realized that it was too low once the yarn relaxes.  I also only had the purple button and a crocheted loop, but I noticed that the underneath ribbing would sag and fold back as I wore the sweater.  

Button 2.0 includes an interior button and loop.  The interior button is a small shanked button that I sewed onto the bulk of the steek for stability.

The purple button is not shanked, so I stabilzed it by sewing it on with a small clear button on the inside (aka an anchor button).  The inside-underneath button keeps the purple button upright ... meaning my yarn loop doesn't pull it over to the side.

TECHknitting recently had a lot of great posts about buttons in which you can learn everything you ever wanted to know and more about putting buttons on your hand knit and hand crocheted garments, inlcuding using anchor buttons.

Ta da!  I am wearing the hell out of this sweater.  I really should start on another so I'll have it for when this one wears out.