I had this plain white hat for ages, and could never think of how to make it look good. I was on the verge of throwing it out. Then I had an idea, I wrapped a long gauzy white scarf around it, wove in a piece of grey tulle from an old skirt, added a brown fabric scrap with unusual pieces attached to it and a couple of pin on fake flowers!
I sewed the scarf and fabric scrap onto the hat. The flowers are pinned on so they can be moved to different places, or colours switched to match different outfits.
The only problem was, the stitches showed through the brim! Whoops! I didn't think of that! I don't think they are too obvious, though. I have thought of sewing some lace over the inside of the brim, but I am not sure.
I might also add a claw clip to it to keep it on my hair.