Professional photographers use big, complex cameras and they produce fantastic pictures, but if you’re a novice a pro-level camera is likely to be very intimidating.
Make sure that the bag you’re going to use can take everything you need and that it’s comfortable to carry. A small secondary bag is useful for excursions and city trips if you’ve got the space to take one.
Raw files contain much more data and they allow you to perform more adjustment if you make a mistake with the white balance or exposure.
Aperture priority is a good choice for travel photography.
Be quick; they’ll become self-conscious if you take ages. If they frown, give them an apologetic wave and move on.
Whatever it is, make a point of shooting a series of images about it. It’s often the details that you recall rather than the bigger picture.
Lots of cities and towns look better at night. Any litter is lost in the dark and the most attractive buildings are illuminated.
Getting up before sunrise on a day that promises you sunshine will reward you with the best light: warm and soft.
Fitting a dense natural density filter over the lens of your camera will allow you to take a very long exposure in daylight.