I found an article that shows just how easy it is to keep your microwave clean. Despite how often most people use their microwave, it’s often neglected when it comes to maintenance.
First clean it with club soda and a wet towel. Then, dry it with a paper towel. You can nuke away food odors by microwaving a mixture of lemons and water in a bowl. Finally, the article suggests to cover any food you microwave with a coffee filter. I personally use a paper towel, as I imagine most people do.
Anyway, read the specific steps at this site and keep that microwave clean!