There's nothing much you can do other than maybe dust it with a can of compressed air.
Make sure to reboot once in a while and that it is in a great surge protector.
Hello! I do not really do anything to maintain my wireless router to be frank! I only turn it off every now and then. It does tend to heat up at times and I believe that it can help to allow it to cool down before turning it back on. I have been using mine for about 10 years and never had issues with it!