Mow the lawn first
Mark the edge line with a string, hose, or spray paint
Use a manual edging tool, half-moon edger, or power edger
Position the tool along the marked line
Cut straight down to separate the grass from the border
Remove the loosened soil and grass
Trim any overhanging grass with shears or a trimmer
Shape the edge to keep a clean, even line
Sweep or blow away debris
Repeat edging regularly to maintain the border