How to attract new developers for your team

In Blends it is one goal to tie strong connection to upstream and users of specific software for the simple reason that we as generalists usually do not have enough knowledge about these specific programs. However, we try to spread our competence of building packages and finally designing an universal operating system. I have implemented two formalisms to provide this knowledge to newcomers: Mentoring of Month (MoM) and Sponsering of Blends (SoB). In both cases I try to solve the dilemma that you finally have no "grip" on volunteers. They could come and go and you never know whether they will finally commit the code they promised to provide. Both efforts are trying to serve a certain interest of the newcomer and I'm offering to trade my personal time for the time the newcomer is working for Debian. The two efforts are not showing an exciting result but something was done that would not have been possible without it. In this BoF I'd like to gather more ideas how we could attract active newcomers to the Debian project.