The soap "scrunchy" bath things are good for scale patterns too. Very flexible, can be stretched to cover awkward contour, isn't abrasive against previous paint coats, oh, and you get about 10m for $1.
For clamps, I've been using the small metal rubber coated spring clamps you see at home depot. They are cheap, very strong, and the rubber coatings help to prevent scratching paint. The small size lets you put several 3-4 on the bait to have a tighter fit to the lures contours.