Thank goodness for the new Hobby Lobby just north of us in Mcdonough!! It stays open til 8, so Christine and I drove up. I think I have been in the old Hobby Lobby in Fayetteville, but this one is BRAND new and AWESOME!! I can't believe I have been missing out. I found my white twill for $6/yd. Also found some wide ribbon. All ribbon rolls are 50% off right now! {It doesn't take a lot to excite me}
I cut and pinned one last night to see what it would look like. Still debating on the trim. The one shown is a light green and white stripe on an angle. It's cute up close, but not real dramatic far away.
These are some trim options I found online yesterday. They helped spur this spontaneous trip to the Hob Lob.
I was trying to find cheaper options in ribbon. The ribbon above is similar to this. Italian Jacquard from here. The next pic is my $2 5yd spool of ribbon.
I really like this, just not wide enough. It's vintage country from here. One of my favorites is the greek key design from mjtrimmings.
Last but not least, alchemy aquamarine from interior mall. 
Charles thinks I will get tired of sewing before I finish 6 slipcovers....I can't disagree. Also, I need to line the back portion because you can see through the twill. I would like to attach the trim in a way that I can change it when I want. Charles calls me the beaver. They are always rebuilding their dams. I am always recovering, repainting, rearranging, etc. our dam.