Whenever you shop online, you should at least try to go through an online shopping portal. They will bring you to the shopping website you would go to anyways, but they receive a commission for referring you there, and then they forward part or all of that commission to you via points/miles or cash. My two favorite portals are the Ultimate Rewards (UR) Mall for point rewards and TopCashBack for cash rewards. EVReward is a pretty cool tool for finding the best shopping portal for the store or product you are going to buy.
For example, the department store Kohl’s often has a bonus of 10 points/dollar at the UR Mall. So if you spend $100 at Kohl’s by following the UR Mall link, then Chase will automatically deposit an additional 1,000 bonus points into your UR account in the following weeks (as always, see full terms and conditions from Chase/Kohl’s).
Here is another example with TopCashBack: I recently traveled on business to Lima, Peru, where I usually stay at the Radisson. Radisson was offering 10% cash back on TopCashBack, so when I spent $450 for 3 nights there, TopCashBack sent me a $45 PayPal transfer shortly thereafter.
Most airlines and hotels have shopping portals that will earn you extra points while shopping, and they all have different bonus offers that are constantly changing, so shop around! As a final note, make sure you read the fine print before you click the link–some portals’ offers are negated by coupon codes and/or can be limited to certain types of products at each store.