The last Denver meet was the first headphone meet I attended in a very long time. If anyone else is in a similar situation, here is my advice:
1. Bring your own music. Be it your phone, laptop, or DAP, it's always best to have your own tunes with you.
2. Bring a connector that plugs into your music source and has a USB-B output (the kind you use for printers, etc.). If the setup has a USB DAC, you should be able to plug right into it with that connector. Not all DACs at the meet will be DSD-capable, so make sure you have some PCM music with you as well
3. When packing your gear for travel, I'd recommend bringing some towels. Not only do they help protect your gear in transit, but they offer a great resting place for your headphones during the meet.
4. Don't be afraid to travel to other rooms at the meet. Last time, the main room got the bulk of the action, but there were two other rooms that had some excellent gear. You can move headphones between the rooms as well, though you should ask the owner first if they are there.
5. Most of my headphones are a little unusual, so I tried to label my headphones at the meet. If you're using aftermarket pads or cables, it's good to point that out as well.
6. This goes without saying, but show respect to all the gear at the meet. Keep your hands clean and handle the headphones with care. If other people are waiting to try out a station, allow them the chance to try it out.