Start with the fewest choices that work
General admission is often enough. Add adult and child tickets only if their price, capacity or entry conditions actually differ. Put any age definition in the description.
Name tickets for what a guest receives, not an internal category your team uses. Avoid two options that appear identical at checkout.
Separate entry from optional activities
An entry ticket gets someone into the event. An add-on can represent a separate activity. Say clearly whether an activity purchase covers a person, a group or a session.
StandWith supports separate entry and activity balances, but does not currently allocate timed slots. Do not use an ordinary add-on to promise a reserved appointment time.
Set capacity from the real limit
Check how many people the event and each activity can accommodate. Do not give several ticket types independent limits that add up to more places than you can host.
Temporarily reserved places can reduce availability while a checkout is in progress. Sold places and temporary reservations are different counts.
Work backwards from costs
List the costs you expect, allow for uncertainty and decide what you want the advertised price to cover. Check the paid-order fee on the pricing page rather than adding a separate card surcharge.
Paid ticketing is currently in testing. Do not announce real paid sales until payment activation and your operating arrangements have been confirmed.