A.,
An easy way to make some extra cash is to participate on research studies for cosmetic testing. There is a testing lab in Carrollton called Stephens & Associates and another one in Irving called RCTS. I do clinical testing internally for a cosmetics company, so I can tell you that it is an easy, safe and usually fun way to make extra money.
Another way is to be a secret shopper. You can go online and fill out applications with many different companies. Usually, the small amount of money or free product you get, is not necessarily worth the amount of time you spend shopping and writing reports, however.
Hope this helps!