I've been asked how to create a header and what font I used (AnAkronism). I have over 800 fonts installed, took me forever to find which one. Font addict, yep! I love alphas and word art, but dont' we all?
It really depends on what program you are using. I used GIMP and created elements in transparent layers. It really doesn't matter what order you create your parts in when you work with layers. I bevelled the title and added a shadow. For the torn paper I bucket filled the layer with white and used free select and cut. I copied that layer and bucket filled the stripe pattern then moved the layer up to expose the white below. I went to the white and added a bit of gray to add dimension. I merged these two together and added a shadow. I pasted on flowers and added a border with the Script-Fu>Alpha to Logo>3D Outline tool. The absolute background must be the background color of the website when using that for a border because edges show and blogger doesn't like png headers for some reason (sometimes they look right sometimes not). When happy with your pieces, flatten image and save as jpg. In GIMP you can save the unmerged header as an .xcf file so you can go back and alter a layer here or there, very important in case you have a problem with it later or want to make a change.
You can make a blog header between a photo program and scrapbook. Create what looks like a header (long and not too tall, preferrably on a 12x12 inch blank page which is 1152x1152 pixels) and then save your image, not worrying about the leftover white to the top and bottom. You can save from your scrapbook factory to have an output size of 800x800 pixels, check your save menus. Do not close your scrapbook program yet. Open in a photo program (not paint) and crop out white. Then check to see what your dimensions are. You want your width to be 800 since most people are still viewing websites in 800x600, yet a site with those specks look great in larger resolutions. Don't make your height more than 300. My header is 800x200. If you need to alter your dimensions only alter the width to 800 and make sure your height is 300 or less. If things are not working out, go back to your scrapbook program and make some changes. You may have to play with your output resolutions if you are getting a pixelating effect.
I hope everyone understood that. I was trying not to be computer geekish and software specific. There are many tuts out there. You could always google "tutorial for making website header in (your program)" and see what you come up with.