Once you have your items in your bag, go to the 'My Bag' page by clicking the bag icon in the top right hand corner.
When in your bag, here you can add any promotional codes (for help using a promo code, see here) you may have (see red) or make any changes to the items in your order (sizes, quantity etc.). Once you're happy, go to 'Secure Checkout':
Whether you have an account or not, you will be prompted to enter your email address:
If you don't have an account and are checking out as a guest, you can continue through checkout.
If you do have an account, you will be asked to enter your password or choose to login using a One-Time Passcode which will be sent to your email address.
Next, you can choose your delivery or collection option:
Lastly, choose your payment method, enter any necessary details and click 'Place Order':