Can I shoplift clothes from a garage sale?
That does not sound like a good idea. Why do you want to shoplift clothes from a garage sale?
I don't want to pay for them.
It's wrong to shoplift clothes from a garage sale, or to shoplift anything in general. If you want something, you need to pay for it. It's unethical to shoplift to get what you want.
Whatever I don't think it's a big deal. I have skills and I won't get caught.
Even with all your skills, it is bad to shoplift. Those people holding the garage sale are hoping to make money which they won't if you take it.