My experience with creating “holds” or mechanisms to free your hands for carving are as varied as the shape and object to be carved. But not as ingenious as Underfoot's massive "balljaws".

For odd shaped objects that are not considered miniature, I use 2 ft or 3 ft. long sewn bags made of a tight durable fabric.. To close the open end sew a Velcro strip near to the lip and another strip a few inches away on the bag. Pour the bag 2/3 full of lead shot pellets. Roll the open end tight until the Velcro strips attach to each other. Then slip the bag full of lead pellets into another sewn bag as a precaution to having shot pellets spew all over. I have done this.

Now you can wrap your carving in the most secure way you wish exposing the area you want to carve. This really works quite well. The bags are heavy, squish able; you can twist them around your carving object. The bags of lead deaden the vibration from striking when use a mallet. I have made bags that when filled are 1.5 inches in diameter up to 2.5 inches in diameter. They can be quite heavy if they are long but it is easy to readjust your carving. I have also made larger bags to fill with sand. These I use as a bed, or sometimes I will let the sand separate into the two ends of the bag and drape it over the carving object if I am using my one of my other devices to hold the object. I have used these for 15 years. They work great and save time when you need to constantly adjust an object that can’t be held by vice jaws etc.

For very delicate carvings, I will use a sponge and cut it to fit into crevices or hollows on the reverse side of what I am delicately carving such as leaves, fins or wings. Sometimes clay works well as a base for the sponge if it is warm and pliable.