Leather pouches are very period for carrying ones belongings. I wear one in my reenacting. Of course, it's under the armor when I armor up, but I can still get to it pretty easilly. I've started hooking my leather costrel to my sword belt by means of a forged belt hook, since I wear that over my armor. I would imagine pikemen did much the same back in the day. Padding of some sort is a must under your armor. I wear a leather buff coat under mine, but for you earlier period types a gambeson or arming coat would be the equivalent. Padded Chausses or hose should be worn under any leg protection.