What I Did: Design, HTML & CSS, tumblr Theming
Jennifer* is a simple, free theme for tumblr.
When I joined tumblr I designed a custom theme for my own blog, then I liked it so much I decided to release it for free!
Jennifer is currently featured in the tumblr theme garden and so far has over 32,000 installs.
*Why Jennifer? The main title font which features in the theme is called Angelina, so I thought it would be appropriate!