Scrub all surfaces with a mild detergent and a sponge or rag to remove all dirt, grease, oil, etc. Rinse surface well and allow to dry. Spot-priming will help the new paint adhere and give a better finished look.
Remove any fixtures and fittings you can before painting and tape plastic around anything you can't remove. Brush or vacuum up any dust and thoroughly wash the walls with Selleys Original Sugar Soap to remove grease and dirt. This provides a clean surface that ensures the best possible performance from your paint.