i am a first time user of overshoes(Endura). i dont know if there is a certain method of fitting them as it took me nearly half hour to get them on and i struggled to fasten the rear zips. i am a size 8 shoe and bought the size 9 L overshoe. i must be doing something wrong or is it because its the first time they hae been worn, i know they are meant to be tight fitting but these seem very tight and yet the next size up is to fit size 11-12 shoe. help!