Using these Wolky Medusa sandals is easy. First, put your foot into the sandal and adjust the three velcro - closed straps on the forefoot, instep, and ankle to your desired tightness for a perfect fit. If you have custom orthotics, simply remove the existing footbed and insert yours. When it comes to sizing, remember the sandals run small, so order one size bigger as a general guideline. For maintenance, keep them away from extreme heat and moisture. You can clean the leather with a soft, damp cloth and apply a leather conditioner occasionally to keep the leather soft and durable. When not in use, store them in a cool, dry place. If you're using custom orthotics, make sure to check them regularly for wear and tear and replace them as needed.