What size of Birkenstocks should I buy to ensure optimal comfort and fit? Considering the diverse range of styles and models available, how do I determine which specific dimensions would suit my feet best? Should I take into account the width of my feet, or are there other factors, such as the arch support and the specific design of the sandals, that might influence my decision? Furthermore, is it essential to consult a size chart to grasp the conversion between my usual shoe size and the unique sizing system utilized by Birkenstock? How do variations in foot shape and swelling throughout the day affect my sizing choice? Could it be beneficial to try on different styles in-store before committing to a purchase? Ultimately, what insights can I gather to make an informed decision that guarantees both style and comfort, while also preventing the discomfort of ill-fitting footwear?