If you want to start today's GDT, maybe working up a nice one with pictures and wisdom, then you can claim it below. That'll minimize wasted effort.
If it is less than 15 minutes before first pitch, then I recommend just using the quick GDT format, which is found in the GDT subforum.
Last year, we had some games that started before anyone set up a thread. In that case, just start the new topic with a post. No need for lineups.
For home games, the format for the subject is:
Nationals v. [Team we are hosting], Game [whichever game of the series]
For road games, the format is:
Nationals @ [Home Team], Game [whichever game of the series]
I forget how we deal with rain outs and suspended games.