One mistake that new bloggers often make is borrowing art work, photo's, and other details from other sites. Even if you overlook or get past any copyright details, using something that is readily available on the internet is not a good way to set up your individual brand.
Branding should be unique to your business and your site. If your site is as successful as I hope it will be, people will identify you and your business with that branding. Once your identity is well established, it can be difficult to change; think of that blue Walmart sign or that K in Kmart.
Once you become well known you would hate to be required to change your branding, the way that customers view you, because of copyright infringements or because a competitor also begins to use the same free domain graphics.
In the end you will do much better developing your own unique identity that makes you and your business or blog stand out in the crowd.