1. Plan before you go.
There is a wealth of information and photos on the internet regarding most places in the world, so do your homework. Find out what is worth seeing and photographing. Tour companies often provide itineraries that you can view. You can also find out useful information like climate, weather forecasts, sunrise and sunset times and also habitats and local wildlife.
Remember also to check if you require visas and any preventative medical treatment.
Planning also means determining what equipment you should bring. Travel as light as possible and bring minimal equipment. Zoom lenses are great for for travel. My new Nikon 18-300mm zoom lens is excellent for this purpose. Think about bringing a super wide angle lens for interior shots. Tripods are heavy and bulky, so think about bringing just a bean bag, gorillapod or monopod. You may also want some filters and an external flashgun. I wear a photo vest for travel as it holds lenses, spare batteries and SD cards and can be removed easily for passing through security. A camera bag will protect your gear but I use a good rucksack which also holds fleeces and waterproofs.
For info, I tend to carry my camera, an 11-16mm lens, an 18-300mm lens, a 2X converter, a polarizing filter, a monopod, spare batteries and SD cards plus a beanbag. I use a Wenger rucksack, and if hiking I bring Wenger walking boots. PS the monopod can also be used as a walking pole.
2. Get local knowledge
Once you arrive, ask locals such as taxi drivers, bus /coach drivers and hotel reception about local sights and interesting places or events that other tourists may miss. Look at local guide books and postcards to get ideas of attractions and the best viewpoints. In conjunction with a local map and compass you should be able to work out the best sunrise/sunset view. Find out opening times and either arrive early before most tourists get there or later in the day when tourists have already visited.
Don't forget to shoot local colour, detail and people. Local markets and shops are great for this.
3. Be safe
One final word on safety. Be aware that you probably have some expensive equipment on you and are therefore a target for robbery or theft or mugging. Try not to travel in dubious areas alone and let people in your group or at the hotel where you are going and when you are due back. Keep a photocopy of your passport details on you plus the telephone number and address of your local embassy/consulate and tour operator/guide. Be wary in the great outdoors for dangerous creatures and obey all warning signs and local rangers/guides. Remember that sand and water and cameras don't mix, so be careful, especially when changing lenses. Finally, remember to wear suitable clothing and footwear, sun block and always have a water bottle handy.
So have a great holiday and take plenty of great photos.