There is a quite popular approach to branches in SVN. It's described here: http://svnbook.red-bean.com/en/1.7/svn.branchmerge.commonpatterns.html
In my project (one-person project with a separate release cycle) I use both release and feature branches and have no problems.
Exact branch policies may vary, here is what works for me:
- Trunk (only one): all automatic tests pass, contains only completed features and bug fixes
- Feature branch (usually multiple): dedicated to a single feature or a bug fix, usually builds, automatic tests usually pass, after completion is reintegrated to the trunk and deleted
- Stabilization branch (may be multiple, but usually one): dedicated to a planned release, automatic tests pass, used to generate builds to be sent to QA, internal/external release tags are created from it, some fixes or even features may be merged here from the trunk