I've just tried using WiX for the first time. For those that don't know, WiX is an open source project started at Microsoft for developing installers using the Windows Installer framework. WiX is supposed to be much simpler than the standard tools, but doesn't claim to be simple.
My only previous experience has been with the installer projects built into Visual Studio, which I've found to be very confining. I'm happy to say that WiX is the exact opposite. I feel like I'll be able to do pretty much anything I want to once I fully understand WiX. The learning curve is pretty steep however.
The best site I've found for learning is the tutorial at http://www.tramontana.co.hu/wix/ Just read through it all to get a good overview then use it as a reference as you start writing your own stuff.
So far, I have just one tip to share. The tutorial shows how to create shortcuts in the start menu and desktop, but doesn't show you how to add shortcuts for all users. Luckily it's quite simple, just add this:
<Property Id="ALLUSERS">1</Property>
Of course, just connect that up to some radio buttons and allow the user to choose whether to install for themselves or everybody :)