Tell me, is it really that hard to put off disposing your empty chips packet till you reach a waste bin? Don't say yes in your head just to be contrary. Littering is not acceptable, especially not when you're in foreign territory. As a tourist your top priorities are probably shopping, site-seeing and relaxing, basically treating yourself to a well-deserved break. However your enjoyment should not be causing discomfort to the local people or your fellow travellers. Don't be a nuisance! If you are just inherently unaware, we're here to help. Here are a few guidelines you can follow.
It's always a good idea to read up on the cultural norms and customs of the country you plan on visiting. Sometimes certain hand gestures you consider harmless may be considered rude in other cultures. For instance, sticking out your index and middle finger with your palm toward your face is viewed as being disrespectful in the UK. A lot of cultures also have rigid rules regarding littering, smoking, spitting and even random things like chewing gum and eating sandwiches. It's apparently illegal to chew gum in Singapore and to eat sandwiches in public in Thailand. Although tourists are generally not expected to be familiar with customs, you should still be polite and respectful toward the local people. Lastly, please don't use phrases from the local language unless you are certain of the meaning, you might end up offending someone instead to bidding them a good night.
It's understandable that you want to take home memories of the places you visit. Yet you have to realise that some places and cultures do not welcome photography. I cannot stress enough on how important it is to follow the signs. It's not only discourteous but also very foolish to take photos inside sacred temples, shrines and mosques where the signs clearly warn tourists not to do so. Furthermore remember to ask permission before taking photos of the "exotic" local people. Sometimes they'll expect financial appreciation in return for posing for a click.
To get from your home to your tourist destinations you will undoubtedly have to journey by some mode of transportation, most likely via planes. Yes, there is etiquette you should follow even when you're travelling. Let's make one thing clear, showering the air hostess with unwanted attention is very uncivilised. While travelling you should respect your fellow passenger's personal space. That means if you're listening to music you should keep it down, and although this might sound a little off-putting but if you know you exude strong body odour then please don't forget to use deodorant. Be polite when voicing any complaint to a fellow passenger about their activities. Don't make conversation where it is not welcome and don't be rude if you want to avoid conversation.
In the end you have to use your common sense to guide you. Be adventurous but sensible and be open but safe. Have a good trip!