There are only a few places where prayer is forbidden - such as bathrooms, cemeteries, or slaughter houses. Fortunately, I have an office that I can pray in at work. When people see my door closed, they know I am likely praying and come back later. When I am away from the home office, I try to find an empty office or conference room that I slip in to for prayer. I also work outside on the farm and I try to find an innocuous place such as behind a truck for prayer. Sometimes when I am traveling I do the same. I just start looking until I find a place where I feel safe and hidden.