Okay, I'm ashamed to admit that I've never done this (yes I should be punished by the DIY gods).
So this past weekend our electric Maytag dryer got some much needed cleaning attention. Here are some tips you can immediately put into action to prevent a dryer fire in your own home (and believe or not there over 15,000 annually):
+Add an appliance brush to a 1/4 inch drill and thoroughly clean all duct tubing
+Vacuum tubing, the lint reservoir, and inside the dryer around the heating element
+Make sure there isn't a birds nest or other animal debris in your exhaust vent
+Use stiff walled or rigid metal duct tubing instead of the plastic variety
+When you push your dryer back against the wall don't kink or crush the tubing
To see more: http://www.homerepairtutor.com/dryer-duct-cleaning/