A frequent response I receive when talking to prospective mentors: "I'm not a Debian Developer yet".
As student applications have started coming in, now is the time for any prospective mentors to introduce yourself on the debian-outreach list if you would like to help with any of the listed projects or any topics that have been proposed spontaneously by students without any mentor.
It doesn't matter if you are a Debian Developer or not. Furthermore, mentoring in a program like GSoC or Outreachy is a form of volunteering that is recognized just as highly as packaging or any other development activity.
When an existing developer writes an email advocating your application to become a developer yourself, they can refer to your contribution as a mentor. Many other processes, such as requests for DebConf bursaries, also ask for a list of your contributions and you can mention your mentoring experience there.
With the student deadline on 27 March, it is really important to understand the capacity of the mentoring team over the next 10 days so we can decide how many projects can realistically be supported. Please ask on the debian-outreach list if you have any questions about getting involved.