Hello, can I help you ?
What size are you looking for ?
What colour do you want ?
Are you looking for a specific brand ?
What shoe size do you take ?
What about this nice pair of sneakers ?
Do you want a plain sweatshirt or a striped one ?
Do you want to try these trousers on ?
How does it fit ?
How do they feel ?
Having a British accent, I changed the American 'sneakers' to the British 'trainers'.