A key trick is to keep a wet edge and work in small sections. That means you don’t let one strip of paint dry before overlapping the next. Load the roller properly (not dripping, but well covered), and roll in a “W” or “M” pattern over a manageable area, then fill it in without pressing too hard.

Always roll from dry into wet, blending the fresh paint into the still-damp area beside it. If you stop halfway and come back later, that dried edge can become a visible line.

Use a decent-quality roller cover suited to your wall texture. Too short a nap won’t reach into texture; too long can leave heavy marks. Also, avoid overworking the paint. Once you’ve spread it evenly, resist the urge to keep rolling the same area as it starts drying — that’s when tracks appear.

Maintaining consistent pressure, direction and speed, plus good lighting while you work, goes a long way toward a smooth, even finish.