Most points/miles programs, have points that expire without use. One common method of avoiding expiration, is to book and cancel an award reservation.
Programs that
WILL extend the life of your points/miles with the book/cancel method:
British Airways
United
IHG
SPG
Programs that
WILL NOT extend the life of your points/miles with the book/cancel method:
Aeroplan (no free cancellation within 24h).
Air France (points expiration only extends by earning miles from flying or CC spend).
Singapore (points expire a set time from transfer / earn date, if you book a flight for past the mileage expiration date and cancel, you forfeit the miles).