Pretty Much if your not after a win and just to finish respectfully then Long back to back days in the Saddle. I did the TW this year had a fitness plan all worked out then was injured so could do much riding untill a month before the event, but during the winter I had put in a lot of miles and back to back days.
As for specific training go out and do lots of LOOOOONG boring fire road climbs as there are loads, these are what I found the hardest.
Bike and kit prep if you have more than one bike select the one your going to ride and pretty much only ride that and get your set up right now. About 3-2 months before get it serviced and take it compleatly apart all nuts etc bearings replace anything that maybe worn. and renew your drive train chain Casstte chainrings. once serviced keep riding it so that its all bedded in nicley.
PD