Depending on the application you might to use a framework like GAMOS or GATE. These framework allow you to build your simulation with a simple scripting language instead of pure C++ code. The simlations can then be easily modified and the time is not expended in code debugging.
This two framework are focused on medical scanner simulation. I don't have experience with GATE, but GAMOS is flexible enough to be used in general purpose simulations allowing to add your own code in order to record the geant4 data and/or implement your own analysis code.