Skyline photography is one of the few genres where preparation matters more than equipment. The subject does not move, the light is predictable to the minute, and the hard part is being in the right place with a stable camera. None of that requires an expensive body.
Finding the position
Almost every well known skyline image is taken from one of four kinds of place: across a body of water, from elevated ground, from a bridge, or from a publicly accessible rooftop or observation deck.
Water is the most reliable. It gives you distance, an unobstructed sightline, and a reflective foreground that doubles the light. If your city has a river, a harbour or a lake, the far shore is the first place to look.
Scout in daylight even if you intend to shoot at dusk. You want to know where you can stand, what is in the foreground, whether there is a railing at an awkward height, and how long it takes to get there. Arriving in fading light to discover a tree in the way is a common and avoidable waste of an evening.
Timing
Work backwards from sunset. Be set up and composed at least twenty minutes before it, because the interval you want begins as the sun goes down and runs for roughly forty minutes after.
Keep shooting across that whole span. The light changes continuously and your eye adapts to it, so you are a poor judge in the moment of which frame is best. Take frames every couple of minutes and choose later on a screen.
Settings that actually matter
Use a tripod. This is the one piece of equipment that genuinely changes the outcome, because at dusk your exposures will run from a fraction of a second to many seconds and no one hand holds that.
Shoot at a low ISO, typically the base value of 100 or 200, and let the shutter stay open as long as it needs to. There is no motion in a skyline to freeze, so a long exposure costs you nothing and keeps noise out of the large smooth sky area where it would be most visible.
Choose an aperture in the middle of the lens range, somewhere around f/8 to f/11. This is usually near the sharpest point of the optics and gives enough depth of field for a distant subject. Going to f/22 in search of more depth is counterproductive, because diffraction softens the whole frame.
Use a two second self timer or a remote release so that pressing the shutter does not shake the camera. On a mirrorless body use the electronic shutter if it is available.
Low ISO, mid aperture, whatever shutter speed that demands, on a tripod. Almost every skyline photograph you admire was taken with some version of those settings.
Exposing for lights
The common failure is blown highlights in the windows. Once a lit window clips to pure white there is no detail to recover, and a skyline full of white rectangles looks cheap.
Expose for those highlights rather than for the overall scene. In practice that means watching the histogram and keeping the right edge off the wall, accepting that the shadowed parts of the buildings will look dark on the back of the camera. Shadow detail in a raw file is far more recoverable than clipped highlights.
Composition
Keep the horizon level. On a cityscape this is unusually obvious, because vertical towers next to a tilted waterline immediately look wrong.
Decide what the foreground is doing. A plain strip of water at the bottom of the frame is calm and works well. A cluttered near shore with bollards and parked cars pulls attention away from the subject. If the foreground is not contributing, crop it out or move.
Think about where the tallest element sits. Dead centre is static. Placed off centre, with the rest of the skyline falling away from it, gives the image a direction and a focal point.
Afterwards
Shoot raw. The latitude it gives you for white balance alone is worth it, given that every skyline at dusk is a mixed lighting scene with no correct global setting.
In processing, resist the urge to lift the shadows heavily. Dusk images carry their mood in the dark areas, and flattening them to reveal every detail tends to produce something that looks like a bright day with the lights on. The sky is the one place worth real care, because banding in a smooth gradient is the most common artefact and the most visible one at full screen size.
