Since the lovely Grace asked, I figured I'd write a little instructional on how I got my background and made my banner without going precisely step-by-step because not everyone has the programs that I use and there are already instructions existing elsewhere.
The background was the easiest because The Cutest Blog on the Block has a huge assortment of blog backgrounds with instructions on how to install them on blogger. My blog is two columns which you can see from the wide column of blog posts and the thin column of links, info, etc. Some blogs have three columns, and so you must pick backgrounds according to the number of columns you are using.
I LOVE clip art from the 1930s-1950s. Most of it is no longer in copyright and is free for public use. This clip art was generally used in magazines and local newspapers at the time just to spice it up a bit.
My two favorite sources online are tack-o-rama (which has vectorized images for purchase) and RetroGraphix (which has a large selection of free clip art but no option to purchase vectorized images).
There are lots and lots of other sites for purchase, and there are some pretty cool books with retro clip art that you can scan and vectorize or clean up in whatever program you want. Three of the books that I've for retro clip art and would recommend are 864 Humorous Cuts from the Twenties and Thirties, Popular Advertising Cuts of the Twenties and Thirties, and Spot Illustrations from Women's Magazines of the Teens and Twenties.
Although it's not retro clip art, my favorite clip art book is 4000 Flower & Plant Motifs, and there's also 4000 Pattern Motifs and 4000 Animal, Bird, and Fish Motifs which I'm sure are lovely too.
If you don't want to buy a book just for making a website, you don't have to - I've used these clip art images in Christmas letters and all sorts. They're very fun, but I'm saying this as someone who really likes them.
To go along with my tiny obsession with clip art, I also love fonts, and my hands-down favorite place to find them is 1001 Fonts. There's more than 1001 at this point. All you have to do is find the font you like, download the zip file, and unzip the contents to :\WINDOWS\Fonts if you're using Windows. I'm not sure what Mac users use/do. Tack-o-rama also has some very cool fonts.
I vectorized (traced in a vector drawing program) two of my favorite clip art images and combined them together. I'm not quick with the pen tool, so it took a bit. However, it's worth it because if I wanted a giant 44"x60" poster, I could. That's the beauty of vector - it works on mathematical algorithms that can be infinitely enlarged or reduced. There's an open source program called Inkscape that's a vector drawing program. I haven't used it, but it's supposed to be good. Alternatively, you can do a very large trace using Gimp because chances are you won't ever need that 44"x60" poster of a single clip art image. I've also used vector programs to create logos for small local non-profits for them to use in promotional material or banners/posters. If vector programs are something you want to get into, then you'll definitely have to read up on some of the tools. There's a learning curve where it makes absolutely no sense at all, but it will click eventually and you'll zoom through.
After designing the clip art combo, I decided on placement, set the banner to 650 pixels by whatever the height was on the image when I was fooling with it. Very scientific, right? The font I used is called Elegance and must have come from tack-o-rama although I can't find it right now. Definitely check out the script font section of the website if you like the style of the font.
If doing really cool banners and graphics is something that intrigues you, you will have to do it all by hand and scan it in or break down and learn some sort of proper graphic manipulation/drawing program. It's a bit weird, but I've largely taught myself and have never taken a class. I got better with practice and searching out answers online. I'm far from the best, but it's a good marketable skill and just plain fun. I've been hunched over my keyboard and mouse (oh ya! I don't use a tablet) for hours, but it was still fun and worthwhile to me.
For a couple of examples of what I've been able to do over the years, check out my Invisible Girl submission to DeviantArt. A friend and I also did some animated clone gif's without green screens, doubles, etc. It was a lot of editing and timing, and yes, I was the actress. None of these are perfect, but that's what you get from someone who hasn't been formally trained and doesn't get paid (or expect to) for this stuff. However, these were probably some of my favorite and most fun graphic imaging projects, so I'll leave you with this blast from the past: