How to create a blog background with your own picture?

Easy! Create a canvas (on an editing software off course) of 1800 pixel Witdh and 1600 Pixel Height. Then edit your picture on the canvas (copy, paste, move, transform, skew, add text..etc...) presto!

Oh yes. You have to save the picture to a gif or Jpeg format of less than 300kB. Below is the latest background I created.