I have two of those cheap black aluminum lights available on Amazon for about $11. I already own 18650 batteries and chargers. They are no where near 1000 lumens but still bright. Been using both at the same time years on and off road in the winter. Aim one a little lower and wide, the other more direct and high, it mimics a high and a low beam. Only problem is tight turns. The only answer for that is a helmet light but any extra weight on my helmet is not comfortable so I just live with it. If i was doing routine MTB off road I'd get something better. I carry two extra batteries and swap about 90 minutes into my ride. If one were to fail during a ride, I still have the other one. I can put one in my mouth or use it as an area light while fixing a flat or whatever during the ride too. A lot of my riding is in pitch black rural areas where you literally can't see your hand in front of your face. I also use them around the house as... flashlights.

Not these exact ones but similar
https://www.amazon.com/Beike-Tactica.../dp/B07L9MP4SY

I have small pieces of reflective tape on my pump and multitool. Makes finding it easier or at least less chance of leaving it behind.