Maybe tape your headlight?
 

I did not see this coming.

Last week I was riding to work about an hour before sunrise along some very quiet rural roads with about 6 more miles to go. One of very few cars turned onto the road with brights a-blazin' so I went to signal a request to off their brights. I've been signaling to cars a few weeks now with very limited results by putting my hand in front of my light and removing it a few times, giving an off/on effect.

This time my hand barely brushed the headlight and the twist-on front (which holds the LEDs, like a flashlight) went flying off and to my right. This is one more reason for me to get a 2nd headlight. I'm using a Planet Bike Beamer 3 and its twist top to the battery compartment has very little twist to it before it comes off. I could not locate the parts and pieces of my headlight so I marked the spot on the side of the road and pedaled the remaining six miles in the dark.

Later I found everything but one battery and the light still works. Now I've got it taped so it doesn't come loose unexpectedly.

I have that same light so thanks for the tip!

When I clip my tail light to the cloth loop on my saddle bag (designed specifically for that purpose), it has a tendency to go flying off when I hit even small bumps in the road. To prevent that, I tape the back of the light so it can't come out of the loop.

Kind of annoying actually.

I'll take that as advice to never buy that headlight.
I have a Planet Bike SuperSpot headlight. It amazes me how the same company can build such a great taillight/blinkie and such a useless headlight. I'm sure they're not all bad though; the Alias HID looks pretty nice.

All the more reason I try to run at least two lights when possible / affordable.

Reminds me of Cateye products most of their stuff, (low end, made in China), is complete pants particularly their lights, drop them and they are damaged beyond repair and don't get me started on water getting into the insides. But I'm told their higher end stuff is made in Japan and is better quality - Never used them as I've been disapointed too many times.

I quite like their bike comps though.

Back in my college days, I had a cheap Cateye light that would fall out of the mount if I hit a speedbump, so I had the thing taped/zip-tied in place.

Since then I've had a CygoLight which worked great, but by the time I had to replace the battery they had discontinued that model; so I bought an L&M Solo, which worked well, but I found the "leftie" handlebar mount to get a little shaky over rough pavement or big bumps, and I had to re-align my light once in a while.
Now I run a Supernova E3, and it's bolted and blue loc-tite'd in place. It's not going anywhere without a pair of vice grips and a ratchet driver.

It's all about a P7 and a universal bike mount.

I use the very same P7 light with a Twofish Lockblock. Last week, I was riding toward a pedestrian. As I passed her, she shielded her eyes and said, "is that really necessary?"

I ride 46km a day to work and it's very necessary. In any case, it's still less bright than a car headlight.

How do those P7s compare with the Fenix L2DPremiumQ5zomgwtf lights?

They're brighter at medium, and have better battery life. Also significantly cheaper.