Painting a ceiling is mostly about preparation and rhythm — get those right and it's a doddle, even if it's a faff working over your head.
Clear the room or sheet everything up, then mask the wall line with FrogTape if you're worried about a wobbly edge. Fill any cracks, sand smooth, and spot-prime water stains or old patches with Zinsser BIN — nothing else reliably stops a stain bleeding through fresh paint. Skip that step and you'll see the mark grinning back at you through two coats.
Now the order of work. Cut in first — use a 2-inch brush to paint a 50–75mm band around the whole perimeter and around any light fittings. Then load your roller and tackle the main field *while the cut-in is still wet*, so the two blend without a lap mark. Work in metre-square sections, rolling in overlapping passes, and always move away from the main window so the natural light shows you what you've already covered. A medium-pile roller on an extension pole saves your neck and gives even coverage.
For paint, a true ceiling needs a dead-flat matt that hides imperfections and doesn't flash. Dulux Trade Supermatt is the decorator's standard for new plaster and big ceilings — cheap, ultra-flat, brilliant coverage. For a quality finish in a living space, Little Greene Pure Flat Emulsion or Farrow & Ball Dead Flat are gorgeous. On colour, most ceilings want a soft white rather than brilliant white, which can feel clinical. Farrow & Ball Wevet or Little Greene Loft White keep it bright but warm; Pointing works a treat if your walls are warmer.
Two coats, always. Let the first dry fully (check the tin) before the second. Don't overload the roller — thin even coats beat thick gloopy ones every time.
Keep a wet edge, don't go back over a section that's started to dry, and you'll be sorted.