I use Adobe Fireworks (the little sister of Photoshop and much easier to use). All my avatars are custom made, though I may use the works of others. Currently, I'm using Kozue Amano's Akari Mizunashi, because I'm in love with her.
*cough*
The image is from one of her manga volumes, though I don't know which one. I don't read manga, and I couldn't find a suitable image from the anime. I super-imposed the "ARIA" text on the image, added a border, and then resized it.
Took about 10 minutes. 40 if you count the time it took to find a good image.
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No sappy lines allowed!