Don't touch the game
That one feature you didn't add? The UI that's not quite there? Leave it. You'll end up fixing a broken build when you could be networking. Treat this as a playtest weekend instead and jot down notes for later.
You'd be amazed at what can walk off in 10 seconds. Chain your laptops, tablets, and lockboxes to the table if possible, and keep an eye on your cashbox at all times.
Refine your pitch
Boil your pitch down to a one-sentence hook you won't mind repeating a thousand times. Flesh that out into a 1-minute version. Expand the one-minute version into a 3-minute press-friendly sales pitch. Prepare answers to common questions.
Enlist a gopher
Some cons have volunteers to help you out with minor things. Find one, and get their phone number. If they're going above and beyond, thank them with some free swag.
Meet your neighbors
Spending three solid days on a convention floor is tiring, grueling and sometimes monotonous. Use the downtime to commiserate and make friends with other exhibitors. The indie convention circuit is small, so you may be seeing a lot of each other.
Discover other indies
To really be a part of this community, you need to know what your peers are doing. Introduce yourself at after-parties. Walk around to other booths and demo some games. Be inspired, and be supportive.
Wear decent shoes
Extra-plush carpeting is way too expensive, so make sure you wear shoes you’ll be comfortable standing in all day. Don't try to break in a new pair of shoes on the con floor, unless you’ve got three days worth of bandages to spare.
Bring a survival kit
Crowds make it difficult to make a quick run. Keep snacks, lozenges, band-aids, pain relievers, hand sanitizer, scissors, duct tape, and other small emergency items you think you might need at the booth all weekend.
Talking, partying, standing, pitching, and running all day will take its toll. Bring a water bottle even if you don't think you’ll need it.
Partying is awesome, but your voice will be shot and you'll be unable to pitch your game if you went too hard the night before. Call it early some nights. Or don't. We’re not your mom.