If you plan to use a bottle to give your baby expressed breast milk, use a bottle nipple that allows the milk to flow out slowly. This is sometimes called a 'slow flowing' nipple. This will allow your baby to pace the feed and control the amount of milk they take.
You could also use a feeder cup or a spoon to feed your baby your expressed milk.
Watch a demonstration of paced bottle-feeding
Expressing occasionally for a bottle
When expressing milk for occasional use, try to avoid expressing late in the evening. This will help make sure it does not impact your milk supply. If you start to notice a slight drop in your supply, going back to breastfeeding for this feed will help.
Keep in mind that your baby will probably not drink the same amount of milk at each feeding. Watch their behaviour, and don't force them to finish the bottle if they don't want it.