Simply select an item from anywhere on this site, choose your preferred size - then add to your shopping bag. You can keep an eye on the total number of items in your bag, and how much you have spent, by clicking the basket link at the top of your screen.
When you have finished adding items to your bag, you will be led to the review order page where you can delete items if you've changed your mind. You will then enter the checkout area where you supply your billing address and the delivery address.