You must follow the rules exactly. Easy mistakes include:

For credit card:

- not meeting spending targets to earn signup bonuses

- not utilizing all the cards benefits (For example, discover requires you click a couple buttons to activate 5% reward.

- minimum points redemption (must have > x points to convert to cash)

- Forgetting to redeem points before closing the account.)

For checking/savings rewards:

- not meeting direct deposit targets

- not maintaining an account balance