Vacuum your sofa regularly with a brushless tip.
Some stains can be removed using a colourless cloth, dampened with a neutral pH hand detergent mixed with water.
Apply the cloth with a circular movement within a 20 to 30cm (8 to 12 inch) radius to prevent a halo forming.
Ink stains should be removed with 60% white spirit.
Always test the resistance of the fabric’s colour first on a hidden spot.