Return policies are very industry and location specific. Following are some main return issues you need to define for your store.
WHAT can be returned?
Are all your products returnable or do some restrictions apply?
WHEN do items need to be returned by?
Set the time limit for returns.
WHERE do items need to be returned to?
HOW do customers return items?
Tell the customer how to return items, what documentation they need etc.
SHIPPING for returns?
Are original shipping rates refundable? Does customer pay for shipping the return?
CREDIT for returns?
Set how customer is credited for returned item.
In store return option?
If you have brick and mortar locations, can customers return items there. Provide locations, directions and hours of operation.
Do items need to be in original packaging for returns?