Yahoo just posted an article (http://travel.yahoo.com/ideas/signs-you-re-a-terrible-travler-222513138.html?page=all), and I think it is worth reading. The tips they posted are fairly intuitive, yet they’re super handy to keep.The only thing I would add is to just be ready to experience other cultures, and not be stuck in an American/home state of mind. Honestly, I’m glad that I’ve yet to encounter any obnoxious travelers, but I’ve heard and seen stories of loud mouthed travelers that didn’t make the mental trip to their vacation destination.
For me, the two biggest things are to do your research and to pack smart. Obviously, the former will make or break your trip from the get go, as you need to know where you’re going to be staying (seasonal travel can jack up prices like no other) and the airfare, among other things. Packing smart is highly underrated I think, as choosing what not to bring is an art. However, from personal experience, you may be lugging that bag of yours over significant distances to get to your hotel, so pack lightly/smartly. This actually can serve to combine both of these principles, as knowing the terrain, both literally and figuratively, of your destination can save you a ton of hassle.
As always, if you have any other stories and/or comments and suggestions, feel free to let me know!