If you get the chance to, always thank cleaning/sanitation staff such as janitors, maids, and trash collectors. Make it known that you appreciate and value the job they do.
Cleaning/sanitation jobs are some of the most vital jobs in society, without them we’d be buried in our own trash and all public spaces would quickly become unsafely unhygienic. Despite how vital their role is to society they’re often treated poorly and generally looked down on by the rest of society. Treating them with respect and kindness and letting them know you appreciate the job they do can go a long way in making their day and their job in general better, and you do want happy cleaning/sanitation workers because of how important they are.