First, you need to research where you are going. Use whatever resources you have to find out what the best spots are and where you will probably want to snap some pictures. Theres nothing worse than going on vacation and finding out later that you missed out on a picture of a famous landmark or scene!
If your travel adventures provide you with opportunities to take photos from a moving vehicle, be it a car, boat, plane, helicopter, or horse and buggy, remember that any sudden movement can turn a great picture into a useless blur. Before going on such an excursion, study your digital camera manual and learn how to increase your shutter speed so that your camera can take photos as quickly as possible.
You may also want to adjust your ISO sensitivity higher to support faster shutter speeds. Note that both techniques may decrease lightness or introduce grain (noise) in your photograph, so you should always experiment to find a good balance.
If you are taking a landscape photo, instead of taking a direct shot at the landscape, consider pointing your digital camera lens upwards to grab more of the sky. It helps if you have a viewfinder that can swivel upward. This type of photograph can signify openness, freedom, and wide expanses, and may result in a pleasing picture.
When doing this, you may want to first consider getting a spot reading on the landscape. Otherwise, pointing your lens towards the sky may result in the camera auto-exposing on its brightness, causing your landscape image to be washed out.
If you do not know how to do this, you can instead try focus locking on your landscape. This will also lock your cameras exposure on the landscapes colors. Then rotate your lens upward and snap a photograph. Experiment to get the colors you desire.
Being prepared is the best thing you can do for yourself when taking pictures while traveling. What will you need? Here is a checklist of items you may want to look through before going on a trip. Of course, your particular travel and photo needs may warrant extra preparation steps and the need to bring more equipment, so add to this list as needed.
Clear and reformat your digital camera media (assuming you have backed up all photos currently on the cards).
Charge all batteries.
Make sure the digital camera and camera bag straps are secure.
Turn on the camera, take a couple of test photos, and ensure everything is working correctly.
Clean your digital camera using a cleaning kit, being careful not to scratch or damage the lens.
Ensure you bring along the following, secured inside a digital camera bag:
Extra filters, such as a UV filter
If you have access to a laptop, you might want to also bring that along in your travels. Even if you do have a mighty, mighty storage card, you may find yourself with two days to go on vacation and all memory cards filled up. If you have your laptop with you, you can simply download your photos every day and start fresh the next.
Do not bring the farm when it comes to your digital camera equipment, especially if you have to walk a lot to cover a cityscape, village, countryside, etc. Limit what you carry. You may not need to bring all of your extra batteries, but just enough to cover a particular shoot. Leave the rest at home or in your hotel room (possibly in a hotel safe).
If you are REALLY into photography and have multiple cameras, you do not need to take all of them with you. A regular-sized and a compact camera for taking quick shots should handle most, if not all, photo taking opportunities. Only bring a tripod with you if it is absolutely necessary as these add a lot of bulk. Be prepared, but not over-prepared in that you wear yourself out lugging around extra unneeded equipment.