Learn How to Make Your Own Theme
You don’t need graduate degrees in the arts and computer science to create your own theme. Sometimes, all you need is a little bit of the talent and a decent graphics editing program. When you are beginning your journey in theming, you can choose one of two paths: modify an existing theme using APK Tool or write one from scratch using one of available IDEs like Android Studio or Eclipse.
For most, the first option seems to be the easier one. If you want to learn how to make your own theme, probably a wise choice is to follow a guide written by XDA Senior Member DanielFlorin. By reading this guide, you will learn what it takes to create your own theme using the eXperia L Orange as a base. You need a good APKTool client, as well as some time and creativity to create your desired theme.
This method described in the guide is pretty good for beginners. You will get some experience that can be used in your future projects. Themeing can be quite difficult sometimes, so you need to understand it better before you start to make your own, more professional projects. Take into account that only select ROMs support theme engine, so be sure to run a compatible one before making your own theme.
The thread has been written to show the theming process on Sony Xperia phones, but this method can be used with other devices as well. You can learn more by visiting the Make Your Own Theme thread.