The big problem with writing, of course, is it is a sedentary activity (though very good for the brain!), so I walk the dog (a) because she needs it and (b) because I do too! The break from the desk can and does inspire creative thought, which is another excellent reason to walk.
What kind of exercise do your characters do to keep themselves fit, assuming they do? What are their walks? What hazards would they face in their world that simply wouldn't happen on Earth? What are the similarities? Going to meet someone of course can be a pivotal point in many a story but where would your characters go if they needed secrecy and can they guarantee this?
Does your created government restrict where people can go? What are the laws on land ownership, rights of way and trespass, if any? These sort of details can help flesh out a realistic picture of the world you're conveying to us as we can appreciate the equivalent of these that we have so it is easier to identify with this.