Do I Have To Give The Sizes When I Order?

No. As long as the wedding is more than 60 days away, then you may click "Size To Follow" which reserves the styles and quantities, whatever the size ends up being. Sizes can then be entered anytime up until the 60-days-to-go point through a link which you will see within your order confirmation email. As well as entering sizes, the link may be used to change sizes that you have previously updated.  If you happen to be placing your order with less than 60 days notice to go to the wedding date, then you must enter the sizes there and then.