It won't do you any good to project that kind of image, but if you really do like somebody's new shoes, by all means tell them. You'll probably make their day, and it cost you nothing. Finally, give people your undivided attention. People will like you more and be more open with you if they feel you have similar interests. That doesn't necessarily mean you have to be an expert on every subject.
Most people love to talk about themselves and their interests.
If you give them permission to do that by demonstrating that you are genuinely interested in what they have to say, people will be happy to carry the conversation for you. You'll learn something new, and the person you've been speaking with will come away thinking you're one of the most fascinating conversationalists in the world. Best of all, as they're discussing themselves and their interests, you may just find out how you can help them to achieve their own goals.