There are tons of teardrop trailer plans and schematics on the web, and because of the popularity of DIY, many of these home built trailers been showing up in Make Magazine and the handy step-by-step site, Instructables.
While these types of sites don't take the place of a well drawn plan, they are a handy tool to see the process and final project. What's also great about these plans is that the trailers have already been built by the owners and they are sharing not only the visual steps they took to build the trailer, but also what issues they run into, how they purchase their supplies and any links they found to be helpful.
Here are a few teardrops that have been featured on Make Magazine and Instructables.
Make Magazine featured Werner Strama and his large, homemade trailer