One thing one can always do is put a wedding photo on your desk. Anyone that puts their wedding photo on their desk is sending a message immediately to everyone “I am happily married so don’t mess with me”. In addition always keep your distance. If someone comes in too close take a step back and say “its nothing personal but my religion teaches mean to maintain my personal space. Even if people call you by your first name, make a point of maintaing formality and calling them Mr. or Mrs.”
If they try to engage you in personal conversations don’t get dragged in, just say “I am a private person and my wife and I agreed to keep our private life private, it safeguards our most precious relationship”
Obviously these things work for both men and women. And since we are frum, we explain to our bosses and co-workers that we can’t touch the opposite sex other than our spouses and children.