0. You have to reach the station well before time. Mumbai locals are very punctual. So get out of your home as quickly as possible.
1. While waiting for the train on the station, maintain perfect distance between yourself and the edge of the platform. Neither go too near or you may risk your life by coming too close to the train nor go too far or you may end up squeezing yourself like others who do not get seats and are forced to stand.
2. As soon as the passengers get down, rush inside to find a seat. If you already have a friend sitting inside, ask him/her to reserve your seat. If not then get ready to be squeezed.
3. If you do not get a seat then make your way in and stand near the window seat. According to my personal experience of using Mumbai locals from last 4 years, people sitting near the window have the highest probability of getting up in the subsequent station.
4. Take care of your belongings. Many people keep their bags, water bottles or chart paper holders(especially civil engineers who need to carry large sheets) on the railings fixed above. Make sure that you dont forget to carry them along with you.
5. Get up from your seat as soon as the name of the station in which you have to get down is announced. Trust me, if you dont get down well in time, you will be dragged to the next station.