When you travel somewhere forget your map and all the guide books for a while. Sometimes it's better to stroll along the streets and discover things that are not listed anywhere in the guides but nonetheless great and interesting and more fun.
Visit local restaurants and bars. They are much cheaper and you can try the traditional specialisties and even meet the locals.
Bring a pillow with you for those long bus journeys.
Do not plan too much. You are on holidays! Also, try to have just your essential luggage, not a heavy suitcase.
Get one of those thin money belts that fit inside your clothes. That way you can carry your passport and money with you at all times.
Be open to everything which may happen to you. There is always something new to learn.