You can download view plugins skeletons here .
In tar.gz you have three files :
PluginEx.cpp and .h : skeleton of plugin
MakeExemple.pro : qmake pro file
To create a new plugin :
Modify PluginEx.cpp, PluginEx.h and MakeExemple.pro
Run qmake-qt4 and make
Copy .so files to you tulip installation dir