If you have a flat roof, it’s a good idea not to let too much snow build up on it. The extra weight can damage your roof and snow buildup can cause drainage issues that can lead to leaks as the snow melts. Not everyone can get up on their roof in a snowstorm though.
One tool that can come in handy is a modest push broom. (This is also a great trick for car or truck roofs.) You can find tools that are designed to give you better leverage to reach your roof for snow removal if a broom doesn’t do the trick.
If the snow is dry enough, you can also try blowing it off with a leaf blower or a hose hooked up to the exhaust of your shop vac. The key is to avoid using sharp tools (like shovels) that can damage your roof.
Whatever you do, don’t climb on your roof without the proper training and safety equipment. There’s no need to try and test your new preps and skills with a trip to the emergency room in a snowstorm, even if you do have all the tools you need to get your car out of the driveway.