Write the policy before you sell
State clearly: whether tickets are refundable, until when, whether transfers are allowed, and what happens if the event is cancelled or postponed. Put it on the event page.
Offer transfers
Letting people transfer a ticket to a friend reduces refund requests while keeping the seat filled.
If you must cancel
Tell ticket holders as early as possible, by email, with the reason and what they get. Process refunds promptly — slow refunds generate chargebacks and complaints.
Postponing
Offer the choice: keep the ticket for the new date or get a refund. Give a deadline for choosing.
Keep records
Note every refund and the reason. It helps with disputes, accounting and deciding next time's policy.