You can easily customize the home screen of your phone through the use of beautiful wallpapers or even self-made wallpapers. There are several sites like iphonewalls.net and poolga.com that provide beautiful and unconventional wallpapers for iPhone 4, respectively. Also one can download applications that claim to provide rich wallpapers for iPhone 4.
Another option of tweaking the looks of your iPhone 4 is by changing the look of the icons which does not need jailbreak. Unlike changing the interface of your iPhone, changing the app icons is simple as well as legal. One has to simply download the iExplorer, find the .png picture for the certain app or apps and change it with your own customized icon or with an icon for the same download from the internet.
The best way to customize the outer looks of your phone is by purchasing a customized skin for your phone. The best thing about customizable skins is that they can be perfectly designed according to your taste and can be adorned with a few lines of your own. Also, customizable skins are not costly at all and you can have different skins for different occasions.
Similar to customizing the skin of iPhone 4 is customizing its case. There are many offline as well as online companies allowing to customize your own case and buy it under their name. There are also sites with pre-customized cases available for purchase. Surf through their large database of iPhone cases and purchase the one that satisfies your needs. The basic difference between a skin and case is that while a skin can be applied to your iPhone back cover, a case is an extra cover that gives a sturdy look to your phone along with additional protection.
Adding custom hardware refers to the addition of the back case made of a material that is different from the original case. For example, you can add a wooden case or a metal case like the original iPhone to replace the available glass case.