I designed this bracket-style holder for my headphones. It is easy to print and does not require supports. The hole allows the screw to be hidden flush with the piece.
Size 100%: X30 x Y50 x Z50 mm
Thickness of part: 5 mm
You can use the following settings, printed on Ender 3:
Filament: PLA, PETG, or similar.
Recommended size scale: 100%
Layer height: 0.2 works perfectly
Wall lines: 3
Top/bottom layers: 6
Fill density: > 25%
Supports: No