After use, your stainless steel sink should be wiped down using a soft, damp, soapy cloth and then rinsed off and dried. Please note that "hard water" can cause a build up of greyish film on the steel causing a discolouration. Dishwashing liquid, Jiff or natural cleaners such as white vinegar and/or baking soda are recommended for a deeper clean as are Magic Eraser Sponges.
You can also use the Blanco DailyClean+ spray which helps to remove limescale deposits from day-to-day use. Simply spray DailyClean+ on the area to be cleaned and leave it for a moment to take effect. Then wipe off with a damp cloth and dry with a microfibre cloth.
Wire wool and abrasive cleaners should be avoided. Steel wool can leave minute particles of wire on the surface of the sink, which can develop into rust marks. Always remove damp sponges, brushes and cloths from the sink to avoid water marks.
Home cleaning aids such as bleaches contain Hypo Chlorides which can damage stainless steel. They should be washed off as quickly as possible and the surface dried as above. These should also not be stored in the cabinet under your sink. Corrosive vapours can leach out and damage the stainless steel. Fruit juices, damp salt, vinegar or any other acidic food can also cause damage to the surface if left in contact with the stainless steel.
Also, a reminder that abrasive cleaners, chemicals used to unblock drains, silver dip-cleaner, salt and vinegar should be diluted as quickly as possible and flushed away.