Get paid to write a review
There are many companies who are interested in getting their name out on the internet. One technique they use is to pay people to write reviews about their products.
This typically involves partnering with a company (or several), writing a review, and posting it online. Depending on the company you can post on your own website or one of many free sites that allow you to post content.
If you have your own website this can be a good way to get paid while creating content.
Write reviews for affiliate products
If you have your own website then you can earn extra money buy reviewing products that are relevant to your website topic. Along with the review you can provide an affiliate link to the actual product. If someone follows your link and purchases the product then you will earn a percentage of the sale. You can read more about affiliate marketing.