Just got into cycling and wanted to get a headlamp. What should I avoid when looking?
Avoid 3*AAA battery powered lights. Avoid alkaline batteries.
Do you wear a helmet? Strap a small but powerful LED flashlight to the ventilation slots. Use a rubber band, luggage strap or a dedicated mounting system. This is a simple and robust
You can use any flashlight, but the more powerful the better. The diameter should not exceed 1 inch, the length 4-5 inches maximum. Lots of high-powered lights in the 150-200+ lumens range that fit the bill. Just decide what battery options you like the best and if you prefer a tight, far-reaching hot spot or a wide, floody beam.
(This is hotly debated in the biking community; I prefer a tight beam on the head but others prefer a floody light there. Each to his own...). Then you still have tons of lights to choose from...
Some high quality brands in the $50-80 range: Nitecore, quark, fenix, ...
Some nice budget brands (buy from shiningbeam.com for reliable quality control and dealer support): ITP, Romisen, MG
My favorite battery setup is 2 AA batteries. Invest in a nimh charger and buy some low self discharge nimh batteries, such as eneloop.
Oh, and the headlamp / helmet lamp should be a complement to the lighting already on your bike. The details of which depends on what kind of cycling you do... At the very least you should have a handle bar mounted "bee seen" light in traffic. The headlamp could be turned on in dark spots to help you avoid pot holes. If doing trail rides I use a flood on the bars and a spot on the helmet (others prefer it the other way around). If you use a rubber gadget called
"two fish lock block" you can mount a conventional flashlight to the bars as well.