For whatever reason I usually go to a convention only to find one of my friends or SOMEONE I know, forgot to bring something. Ususually something that should be common sense to bring. I'm mainly talking to the convention kids who for whatever reason seem to think it's alright to forget body wash and shampoo and think "Hey, I forgot it, might as well not bother showering for the next three days"
No, I'm not kidding. I've seen it..or rather, smelled it unfortunately. Honestly how can people forget things like this? Its like people who forget their wallets or cell phone before a long trip. These should be the FIRST things you put in your pack, and the LAST thing you check to make sure you have before getting into the car. Now I understand. somewhere in the middle of everything you just forgot something, it happens to everyone, including me. Hence why people really should make a packing list before they travel. It really does save you time, and grief, if anything I usually keep things I normally bring to con in one suitcase and never move them. That way I always know they're there, even though more often then not I'm STILL checking to make sure they're with me.
So now without wasting anymore time I give you my packing/to-do list. This is in no way a complete, end all list. This is just what I take and hopefully you'll note a few things that should always be brought when traveling.
The bare essentials: (Things I would never leave at home when stepping outside for longer then checking the mail)
Wallet, keys, watch, Cell phone.
Whats in my bag of holding: (No really, it's a bag of holding, and this is going to be long!)
Pepper spray, Colgate Wisps, Headphones for Cell phone/MP3 player, condoms, Lip balm, small tin of altoids or mint,
Gorilla duct tape wrapped around a sliced up hotel key card (to save space), IMCO lighter (For the unique look, no one I know has one aside from me), Simple folding knife, and an old 5 mega pixel camera (if this one were to get lost or stolen I wouldn't be too torn up about it)
First Generation PSP and DS Lite (I goto anime conventions too, gotta have something to nerd out on the way there)
First "inner" pocket:
3 note pads, 1 simple pocket pad, 1 plain paper moleskin and 1 Rite in the Rain memo/grid book, Hand sanitizer, 3 writing tools: 1 carpenters pencil (I can cut it with my knife in my bag to get a new tip should it break), 1 pen and 1 clicky sharpie marker, Kiva backpack (In case I need even MORE space), 1 dreamcast memory card (I play fighting games at conventions when they have them. More often then not on dreamcast they might have the game, but not a save file to unlock everything. So this has 'saved' the day for the 'tournaments' in the past so I keep one in my travel bag).
Second inner pocket: (This is mostly my medkit portion)
Small travel deodorant (Ya know, in case I need it at a moments notice, or if one of my roommates forgot theirs by being a complete idiot.), Nasal decongestant spray, Burt Bees muscle mend (Rubbing balm), small travel bag of antiseptic wet ones, Gold bond foot powder, Small medkit inside of a simply sandwich bag (Has band-aids, painmeds, gauze pads, tweezers. you get the idea.)
Third "inner" pocket: (This is mostly just random stuff I couldn't suit with the rest of the stuff)
2 cheap 1$ ponchos from walmart, MSR pack towel (Has saved my ass numerous times. I usually have towels in my car but this thing is so light there's no reason not to keep it in my bag), a lightmyfire spork (Living out of a hotel rooms means often you're bringing some sort of food with you. So this is a big help), small "drink mix" bag, nothing to help with alcohol, mostly just a few packs of crystal light, hot chocolate, tea and instant coffee, along with some emergen-C to help keep my immune system up to snuff), spare charger for my cell phone along with the Turbo charger. It runs with one AA battery meaning if my battery and car battery were dead and needed to use the phone to call a tow-truck or someone, I could.
Phew..that's it. well, all that I carry in my bag. And I should also notice I carry this bag with everything I just wrote inside of it normally anytime I'm going further then the grocery store. More or less I'm usually prepared for just about anything.
And of course you want to pack your share of clothes, bodywash and shampoo. Plus and medications you would otherwise need. Plus assuming you're planned on going to a convention too, spare memory cards for your camera, along with costumes, and of course your travel itinerary, which I recommend making two or more copies of, one to bring with you for if there was any hang ups or snags you have proof you paid for your hotel room and what not, and the other copy for your friends and family (that way if something goes wrong they know where to call to make sure you arrived safely)
All in all I'll let everyone decide what they should, and shouldn't bring but please for the love of god remember to bring whatever you need to shower. riding in an elevator with someone who's been running around like a maniac for two days in a row, hasn't changed their clothes nor showered is not fun. And yes, I have seen it unfortunately.