First thing is to get a signed bill of sale, with model, year, engine number., and cost, since many states will require that you pay sales tax. Have it notarized if you can, since some states won't accept it without that.
Most places will require that a state police officer check the VIN (the engine number with an A) against the bill of sale and the application for a title. Also, some states will require that the car actually be running and roadworthy before they will issue a title. Again, a state police officer will have to inspect it.
In any case, just hope you get a kind and understanding person at the DMV, and not some jerk bureaucrat who just want to cause pain.