First thing would be to get a gun.... although I witnessed once an interesting scene.
I was commuting in university and was often pretty late. So not a lot of folks on the train. Once, I sit there listen to my music and see a couple in the opposite seat through a reflection in the window. Suddenly a dude puts a hand in his trousers. I am slightly amused, thinking that he is going to pull out his best piece. The dude pulls out the real gun, gives it to woman and she hands a bunch of money over. Boy, did I my best pretending to be asleep!