If bikesandcode's suggestions aren't enough you could always paint your mudguard reflective like this: http://www.instructables.com/id/Paint-your-bike-bicycle-gear-reflective/

There are some other suggestions on the same site for wrapping the frame in reflective material.

If bikesandcode's suggestions aren't enough you could always paint your mudguard reflective like this: http://www.instructables.com/id/Paint-your-bike-bicycle-gear-reflective/

Like this:

There are some other suggestions on the same site for wrapping the frame in reflective material.