Demonstrate your interest in them
Being a good listener is much more important than being a good talker. Demonstrate your sincere interest in the person you are flirting with. The best thing you can do is to ask questions. Ask what sort of hobbies the person has. Find common interests and discuss something that both of you practice on a regular basis: reading, watching movies, gardening or cooking.
Ask them to let you keep one of their items
This tip might sound a bit extreme. We agree that you might not yet be ready to ask for an item that the person has and keep it for a while as a souvenir. You might ask for their sunglasses, scarf or baseball cap. Take a photo with their item on you. Return the item if the thing is expensive.