If you're rooted, there are several roms that not only change the look of your device, but optimize customisation. Just make damn sure you download and flash a rom compatible with your framework, kernel, device, and recovery. Always make a backup beforehand. If you're either not rooted or unwilling to take the risk, nova launcher, go launcher, apex launcher, and others have a myriad of other themes that are simply superficial; but come with neat tweaks such as modifying the number of rows and columns in the app drawer and desktop, as well as others.