Get your ladder, tape, brush, roller, extraction pole, and tray.
Tape around corners and edges and down any lights.
Use a brush to paint the corners.
Using the roller, start in the corner, and move in a parallel motion fluidly. Roll as far into the brushed sections as possible.
Once done with a large part of the ceiling, lay off the paint while it is still damp. This will make it smooth.
Wait for the first coat to dry before applying the second coat.