First, always check the care label.
If it states that the item is washable, then use a detergent without a bleaching or brightening agent to help keep colours at their best.
If the item doesn't have a care label, ask your dry cleaner for advice.
Remember to wash matching items the same number of times so one doesn't fade faster than the other.
Trimmings on garments can affect how they are washed or which product is used. For example, if a garment has a leather collar the care label may say 'Dry Clean Only' even if the rest of the garment is washable.