First, the outside.
How does your phone look like when it’s locked? Is it sleek? curved? colourful? How do you like it?
Suggestions: A stylish back cover or flip cover often enhance the looks of your device of the original want as good or was simply a compromise due to pricing or something else. A metallic cover looks great anytime though some may prefer colored panels.
Then, the inside.
1. Since you’re only concerned about looks, there are a lot of launchers in the Play Store. Take your pick. My recommendations: Yahoo! Aviate, Smart Launcher 3, Themer, Buzz Launcher and Arrow Launcher. All of these have the right blend of looks with functionality.
2. Later when you concern yourself with greater functionality, you may look up custom ROMs for your device. Be warned, do proper research before you flash a ROM. XDA Forums and Quora are two good sources for information and advice.
3. Apps: Keep up with the times, update your apps. Most companies or developer groups have applied concepts of Material design in their apps, which tells any bystander that you’re already up to date.