Kathy,
I took two Craftsy classes recently. Both were with Debbie Caffrey. She showed how to put my left hand palm on the edge of the ruler and spread my fingers out in such a way that AT LEAST pinkie and ring fingers were off but against each other and that left edge. Then the index finger and tallest fab out towards my right. Think Spock from Star Trek. Hand is FLAT not raised up in the air. I also have learned to cut a shorter distance, hold cutter in place, and reposition my hand further up the ruler, when I'm using a 24" length. She also says repeatedly to move your tools and body, not the fabric. My cutting table is now positioned in the middle of my room so I can cut from three sides. If you have the opportunity to take both of her classes, I think you'd be impressed with her methods for productivity. I'm putting many of her methods on my 'habits I want to develop' list. I found most everything she demonstrated to be beneficial. I just need to practice some of them so they become second nature to me.
Thanks for the info. I too thought that the most beneficial dies will be anything without straight edges. Sometimes a proper ruler for triangles or diamonds is all that's otherwise needed. But Debby did explain how to accurately cut them from strips of fabric. She even supplied cheat sheets so a person doesn't have to look things up all the time.