Which ones? The Spinning Wheel 36 that goes on the tack is fun and easy to use. The others that you have to hold the ruler steady with your Machinger gloves while you hold the foot against the ruler, are a bit trickier. I tried several things under my rulers to help with the slipping and the best thing so far is the rubber shelf liner stuff. Gina Perkes shows using her rulers on YouTube and Thequiltshow and she uses little squares of the shelf liner if you want to see them in action.