Recently I had mounted the wide angle (18-55mm) lens on a 20mm + 12mm extension tube combination. I was taking close-ups of a few flowers when I noticed a spider on one of the flowers. As the spider was sitting on the underside of the flower, to get a picture, I had to twist the flower and hold it while taking a picture.
While doing so, I noted that holding the flower by hand was causing the flower to shake a lot. Attempting a macro shot with that much shaking was impossible. Idea dropped.