This is how I make mine on my iMac, iPhoto, and Paintbrush (Same as MS paint). Now if you are a PC user, you will need to get creative. And yes, I do have this vending machine made. It's made to trump even Juggernog!
About this creation
First, you're going to want to make a vending machine with one color scheme. Then, find a perk (From COD:WaW). I have chosen Shades.
I went into iPhoto and churned this version out since the vending machine I've made for it, is orange. Now for a PC you may want to use Photoshop or some other photo editing software.
I start out with this base. Now this pic may not suffice. Just mess around with the shapes. I made it out of two hollow circles, a triangle made of lines, and a square. Then I just recolor it to my desired needs.
In this case, that color is orange.
Then, I went into Microsoft Word (For the iMac) and resized it to fit in this circle.
Last, is to add the name in a cursive font of your choice. Once the decal is done, you can print it on any sticker paper out there. Heck, I use postal label paper for mine! However, the size may need to be changed in order to fit on a Lego brick. That's all for now. If you wish to know anything more or are confused on something, just ask in a comment and I'll do my best to help.