We always recommend to ensure interior woodwork is thoroughly cleaned and lightly sanded – even if using an adhesion primer! Never sacrifice prep! This will add durability and possibly many years to the life of your paint system. This is especially true for the likes of kitchen cupboards where grease can build over time even if you can’t visibly see it.
Clean thoroughly with an appropriate cleaner such as sugar soap, Krud Kutter or methylated spirits. Rinse with clean water after using sugar soap or Krud Kutter and dry. Then lightly rub down the substrate with a fine sanding sponge or sanding pad and use a tack cloth or damp cloth to remove any dust. (Use methylated spirit on exterior woodwork.)
Then use an appropriate primer depending on if your wood is previously painted or bare and topcoat according to instructions.