I use longer tool handles for many of mine. For hollowing tools, my handles are 27 - 30 inches. I normally make them from ash and don’t add any weight. I start with 8/4 material and I turn the back of the handle to a triangular shape. Look for an article about how David Ellsworth turned his handles - it’s great because it provides a more natural fit in the hand, reducing the tendency to grip more tightly. I’ve found it helps with my overall tension, including in the back.