Con Survival Kit
After searching the internet we've found a great Con Survival Kit. "Courtesy of Cosplaying on a Budget on tumbler. We've added the meat below with a few other things we think you'll be needing. To see the full original article please click the link above.
Adhesives: Hot glue gun and glue sticks, super glue, packing take, masking tape (wonderful for fixing a ripped hem if you can’t sew it). Toiletries: Travel size tooth brush and toothpaste, ear plugs, and deodorant. (edit: I forgot to add disposable razer and travel size shaving cream)
First Aid: Mini first aid kit, band-aids, Advil, tissues and glucose tablets (good for people with low blood sugar)
Wigs & Hair: Comb, elastic bands, bobby pins, and a spare wig cap. Cosmetics: Eye liner, lipstick, file, fingernail polish and fingernail clippers. Sewing: Fabric scissors, paper scissors, pins & needles, white thread, black thread, seam ripper, fray check, and safety pins.
Costume Repair: X-acto knife, screw driver, pliers, black sharpy, and a pen.
Optional Custom Items: If you a have something that is painted bring paint and a brush for touch ups. If you have bad vision be sure to pack your spare glasses or backup contacts.
A few granola bars never hurt to have handy. “Shout Wipes” are a life saver for cleaning spots or stains out of costumes. If you have a spare phone charger it’s a good idea to keep it in the bag. A Travel size lint brush is also handy.
Adding to the above make sure you have energy bars, trail mix, or something that you can snack on that won't ruin your makeup.
Water! Water! Water! Please hydrate yourself properly starting a day or two before the con. And keep yourself hydrated during the con. Waiting until you are thirsty to drink water, the day of the con is NOT keeping yourself hydrated properly.
Depending on what you are cosplaying, a "handler" would be a great person to have along. If you are in a builky suit of armor with giant hands for example. Having a friend along, who is in or out of cosplay that can help you do normal things like, twist a door knob, or hold the door open. Would be useful, or helping to patch and repair areas of the cosplay costumes that you couldn't reach without being...well, naked. (yes this should be common sense, but....I've seen it happen.)
And Hopefully this won't be needed but make sure you have a simple change of clothes. Just in case your cosplay costume of choice for that day can't be repaired on the spot. At least this way you can enjoy the rest of your day without having to go home, return to your hotel room etc. Find the silver lining. (T-shirt, shorts and shoes would work well.)