An intern I supervised recently asked me to be a reference. Here are a few suggestions I made to her:
Here's what has helped me be a good reference in the past. If you pass my name & info to a potential employer/application, let me know (an email is fine) so that I can be prepared when they call. If you can tell me anything about the type of opportunity or any other info, that's all the better. Make it easy for someone to be your reference.
Also, one thing I list after each reference when providing a reference list is how they know me.
Professional reference: ____ can speak to my time management and project coordination skills.
Personal reference: ____ ran the volunteer program at my church and can speak to my commitment to x or y.
This helps your recruiter know what to ask of a reference. Anything you can do to make the recruiter's job easier is a good idea.