Get a Seat Alone on the Subway

Some people on the subway are nice, but most are oblivious to anyone else's existence. To ensure you have a seat alone, follow these simple steps.

Steps

Determine whether it is worth putting someone out of a seat for your privacy.
Think of different reasons to keep that privacy, as it may be asked why you need a whole row to yourself.
Make yourself undesirable to other people. Act obnoxious, secretive or strange.
Be very talkative. As most people on the metro will not wish to chat with a stranger, this is a good way to make a bad impression.
"Accidentally" spill something on the seat next to you, creating a small stain which no one will want to sit on.
Sit away from the doors, as newcomers will look for the closest seats once they are on the train.

Wear stinky cheap cologne.
Try using a crutch, and elevating your leg over the seat.
Be very chatty, most people will move to the next seat.
Wear very vibrant colors. It may seem odd, but this will often make others stay away rather than choose a seat next to you. It sends the message of someone being in the seat, whereas, when dressed inconspicuously, people will treat you as an empty seat.

Being chatty and being rude are very different. Don't be mean or offensive to your seat-mate as they may inform the police.
If using the crutch trick, don't use it for just one day, as most subway riders are regulars and may return.