I didn't manage to finish my game for Ludum Dare 24, but I did end up with this little random island generator. It was my first time trying anything like this and I was under a lot of time pressure, so I was basically making it up as I went but I'm still quite happy with how it turned out. I had a hard time finding good and easy to understand articles on the subject so I wanted to share my approach in case anybody else finds themselves in the same situation one day.
Click for a step-by-step of how it's done.
If I had more time, the first thing I would improve is to add a step between 7 & 8 to curve the sections to create a more natural shape. More features such as rivers, lakes, etc and terrain types like desert, snow, etc would also be cool.
Let me know if you have any questions and I'll do my best to answer. Or if you have any suggestions on how it could be improved that would be awesome too!