I recently went to Edinburgh. I have some amazing tips for if you are going. Mama Said is a shop located half way up Cockburn Street. It has an amazing selection of soft drinks, as well as an ok selection of booze. I recommend the soft drinks though. They had some crazy stuff! I had a can of ice cream soda, which was incredibly sweet and had a stange ginger beer after taste. Wish I had taken a photo of the can, but I didn’t. Anyway, the owner of the shop was saying that he discovered the drink when he was down in England buying a car. It was two cans for a £1. Recommended. The other tip I have is for taking the train to Edinburgh. Normally I take the bus as the train is super expensive. However, at the weekend if there are 4 of you going buy your tickets at the train station. There is a deal where it is only £20 return for all 4 people! Baragain!
Make sure that all 4 of you are coming back together though – I got caught out with that once.