If you have removable insoles already in your shoe, follow these steps: Step 1: You should remove your current insoles and place it in front of your new BarefootScience insole. Step 2: Trace around the old insole. Step 3: Grab some scissors and start trimming that outline. Now your new insole should match and fit perfectly! If you don’t have removable insoles, it would be best to go with a 3/4 length insole. But if you want the full size, take these steps: Step 1: Trace your foot onto the new insole so you can ensure your toes can easily rest on it. Step 2: Either trim the insole that is in your shoe or place your new insole above it. There can be a sticky substance underneath the original insole and if you are going to move your new BarefootScience insole into different shoes, it can make things messy. Step 3: Wear your shoes and start strengthening your feet!