To make myself look more touristy, I always bring a map. Also, I’m not afraid to ask for directions if I get lost.
Believe it or not, acting like a tourist helped me a lot when we were in Mexico City and accidentally ended up in the wrong neighborhood. Seeing that we were tourists that are trying to find their way back to the hotel, the locals were more than happy to help us (and save us from getting robbed or killed!).
Using a map is a pretty smart tip. You can rely on your smartphone the whole time!