we are using the windeployqt tool that comes with Qt to package Windows desktop applications.
First you build your application in release mode with the Qt-Creator to generate the shadow build directory, then you use the windeployqt.exe of the same compiler to package your build, like this (command line):
<Path to Qt>\5.4\<Your Compiler>\bin\windeployqt.exe –qmldir <Path to the Shadow Build>\qml <Path to the Shadow Build>\release
Then you should be ready to go. Let me know if this worked for you!