Learning GTK / GUI Programming

[Rick Sutphin <sutphinc bellsouth net>]

Hello,

I am a newbie who is trying to learn GTK+, and GUI programming in
general. I have gone through the tutorial, and have written a couple
simple programs. 

What I am having trouble with, is trying to learn to write/design larger
applications. The programs I have written so far have been ugly; full of
global variables, and with the application code tightly coupled to the
GUI code. 

Does anyone have any suggestions of how to learn to write clean well
designed GUI applications (in GTK or just in general)? 

Rick