Royal Ascot...Booked!

I've booked two tickets to the Royal Ascot! I am SO excited and am freaking out a little bit about my dress and hat. I've been looking for some inspiration.  

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Some of the hats are really over the top. It might be kind of fun?  

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I suppose first I should look for a dress, then the hat. I love the 'Katlin Tango' dress at Reiss. Suggestions?