Option 1: The classic angled brush.
Load the brush with paint by tapping it into a shallow spot in your paint pan.
Next you want to run the brush near the edge but not to it. I find that this pre-painting helps distribute paint and quickly covers the area without having to slow down to get all the way into the corner.
Finally, when you’re ready to get right up to the edge, turn the brush so it is parallel to the line you want to make. When you push the paint into the wall the tip will fan out, so it’s best to start away from the edge and work into it.
And then you just have to watch your line and go slow. It takes a little time, but it saves time from all that taping you could be doing.
Option 2: The beauty of the SHURLINE edger.
This edger creates good coverage, a straight line, and saves on having to watch things too closely. It’s like a paint spaceship of love and wonder.
The Shurline is best used against the ceiling or an edge where the wheels at the top can meet that surface, keeping things in line, while the pad with paint covers the wall.
Just dip into paint.
Get enough paint that the ends are saturated, but not so much that when you apply pressure drips form.
Place the shuttle up to the edge, or just below and then drive into the edge until the wheels touch. Then just let the wheels guide you as you pull the shuttle down the line.
The tips of the pad stick up just enough to meet the corner without oozing and gooing up the line. (But it is still good to watch and make sure the line is keeping where it needs to be. Sometimes if there is too much or too little paint on the pad the line can be too thick and ooze out of it’s place. If it is too little then there isn’t enough coverage and you end up with gap.)
When done correctly (which is not rocket science in any way) the result is a beautiful straight line with enough coverage that you won’t have to re-cut-in.