I wanted to give my blog a more updated look, something unique to me and to the blogging world. However, I wasn't quite ready yet to take a plunge and pay a pro to design it. I was toying around with PicMonkey to design my header and background image. It is so much more than a way to edit images. You can also use it to design many things, such as a logo, header, fliers, posters, etc. I HIGHLY recommend giving it a look.
There are several tutorials out there that people have posted to help you make a variety of things! I've listed some that I have found below.
And OF COURSE, if none of these tutorials help you out, there is always Pinterest!