I spotted this cool hack yesterday for a front light. Take a look at the rather nice looking bike.
Upon closer look I saw that the rider had zip tied a piece of metal tubing under the front rack to act as a platform for securing the light.
The only two downsides I can see are that it is a bit hard to reach (no biggie though) and it might get drenched with water coming off of that front tire (but most lights these days are water resistent). Overall a dope idea for sure.