1) Collect the names of the people you expect (or hope you can convince) to vote for your candidate ahead of time.
2) Categorize them as how much help they need to vote; i.e. pushing via calls, etc.
3) Guess when they should (by time) vote.
4) Track who votes at each poll on voting day.
5) If a voter does not show up when expected, call them. If they need help getting there send someone to pick them up, etc.
Obama's team has been as master of this like no other.