Switching focus to developing my own web applications

Over the past five years, I've designed and developed a number of completely custom websites and web applications.
However, recently, I've been using Wordpress and Drupal in order to keep the costs down for my clients, but I've realised that it has also taken much of the fun and adventure out of the whole process.
As I'm very much driven by challenges, I've been thinking of switching my focus towards developing my own software and so now I've decided to just go ahead and do it.