"The works of your hands" indicates something that comes from man's mind, not the Creator's. Their gods were their own creation, even as their standards were their assessment of right and wrong. Regardless of how men approached life, whether religious or irreligious, atheistic or agnostic, their gods and standards came from minds not in contact with the true God.
This has interesting and devastating ramifications. The nature of idolatry is such that its effect is more subtle than with other sins. The trauma it produces is usually obscured by the penalties brought on by other sins that spring from the original idolatry. Sometimes, the penalty comes so much later that it is virtually impossible for the carnal mind to connect it to the idolatry that began the process.
But the effect of breaking commandment number one is to break number two. Once a person is no longer worshipping the Creator, he must put something else in His place. Man will worship something, and as we have seen, what he worships is almost invariably himself! Even when he is worshipping the works of his hands, he is worshipping himself because he created his idol.