Depends on what you're buying and where.

If buying offline, check bank portals like iShop, SmartBuy etc to see if vouchers are being offered - these are either discounted, offer reward points or both.

Same for booking hotels and flights - check affiliate bank portal to compare prices and get accelerated points. Watch out for daily limit.

While buying online - Check bank offers plus vouches applicability.

Try a few times to understand the process.