If you like to play around with beads, you can do plenty of interesting things besides attaching beads one by one to your canvas. Sew Guide has an outstanding post with ten easy beaded flowers. All of them, except the first, would be really easy to make on canvas, using various beads and sequins. All the tutorials are shown on fabric, but you can easily translate them as is to canvas.
With these innovative flowers, you’ll get some unusual effects on your needlepoint.