There are several freebie websites out there. The key is to sign up for freebies from reputable websites. Large companies such as Proctor and Gamble will often offer free samples when you sign up for their email. Often times there are a limit to the number of freebies given out, so it is better to stick with large companies. There are also companies such as PINCHme, Influenster, and Social Nature, which give you freebies in return for a review. You could also email companies and ask them for freebies or coupons as seen here.
Tip: use a separate email to sign up for freebies