A good ad sells faster and at a better price. Recommendations:

• Clear photos, in natural light, from several angles: full frame, drivetrain, wheels, wear spots.
• Full specifications: make, model, year, frame size, component group, wheel size.
• Actual condition: honestly mention scratches, approximate mileage, parts changed. Transparency protects your sale from disputes.
• Documents: if you have the invoice or service history, say so — increase trust.
• Realistic price, relative to the market and condition of the bike.