There is a mind numbing amount of considerations when packing for your photography trip. Such as which lenses you will need, how you are going to store your photos and how you are going to carry it all around. Then there's the pleasure of getting it all past the ever tightening luggage restrictions of airlines. A little forethought and planning can help make sure you don't get stuck without essential equipment and aren't burdened by what you don't need.
The gear
Perhaps the most obvious consideration is the camera and lenses. If you have planned your itinerary already you will have an idea of the types of shots you want to take. If you haven't, stop what you're doing right now and do this first. Once you know what photos you want to take, you can decide on the lenses that will best help you take them. Thinking landscapes? Then don't be without your wide angle lens. Intimate portraits? Maybe a mid range zoom would be useful.
If you are debating taking a spare camera body then don't. Debate that is. Pack it. The last thing you need is for your camera to be stolen or break while on the road. You might not be able to find a repairer, and if you do they might not be able to fix it on the spot. That would be the end of your photo taking adventure right there. Don't learn the hard way for the sake of a little extra weight.
Then there are all the accessories that may or may not come in handy. Should you pack that set of neutral density filters? Again, think of the types of photos you will be taking. If its landscapes, then yes, by all means put them in. If its portraits they are probably just going to take up space. This goes for the tripod as well. Usually, travel portraits are taken hand held, usually with abundant light. Landscapes however tend to be early morning or late afternoon.
Storage
Once you've figured out what your going to need to take your pictures, you need to put some thought into how to store them. Should you take your laptop, a portable hard drive or two, a bag full of memory cards or all of the above? How much storage you will need depends on how long your stay is and how much shooting you'll be doing. A laptop is useful if you need to view images as you go, or want to do some editing back at the hotel room. But if not, its just one more expensive piece of equipment you need to worry about. Leave it at home. Some portable hard drives have a viewing screen so you can review your photos as you upload them, which can be handy to see if you have the shot you want and gives you the chance to go back and try again if you missed it.
As a rule, it is a good idea to have two copies of your images as hard drives are notorious for failing at inopportune times. If you have a good supply of memory cards, backup to a portable drive and store the used cards is a separate place.
Getting it around
There are a few different options for carrying your gear around with you at a location. Shoulder bags tend to be able to hold a large amount of gear, but have the disadvantage of all the weight hanging off one shoulder. These bags are a good choice if you don't have to do too much walking, but carrying gear around like this for days can do serious damage to your back.
Backpacks have the advantage of distributing the weight evenly, making them ideal for locations where you will be doing a lot of walking. Many of them also have the extra benefit of not looking like camera bags and so tend not to draw as much attention.
Many considerations go into packing for a photography trip. But think it through and take the gear that suits the style of photography you want to do and the place you are going and it will allow you to focus more on what is around you when you get there, rather than trying to decide which lens to use and missing the shot altogether.