Great idea for a post! I'm a fan of night riding, but it is definitely a whole different experience from day cycling.
I agree with everything in the OP about using both lights and reflective materials. I recommend using both a bike- and a helmet-mounted light. My bike mounted headlight rides on the front rack and is powered automatically by my dynamo hub, which also powers the steady-on taillight out back. My helmet light attaches using a Go-Pro style mount, with the battery in my backpack.
It is frankly faster and easier to mount both light and battery on the helmet, but at the cost of battery choice and capacity, also a heavy helmet. My current helmet light and battery are good for at least 6hrs of continuous use. I know because I ride with lights on whether it's day or night. Even in the day, lights are more visible at greater distance than brightly colored clothing.
For safety reasons, I recommend making sure your light configuration is not 'normal' relative other road users such as automobiles or motorcycles. To paraphrase Sheldon Brown, it's better to inspire a motorist to lift their foot from the accelerator as they wonder 'what the heck is that?' rather than the alternative <thump> <thump> 'what the heck was that?' A bit macabre to be sure, but when it comes to safety, it's sometimes best to speak plainly and clearly.
In any event, if you use lights which require replaceable batteries, it's smart to keep a spare set with you if possible. I'm thinking here of those lights still powered by AA or AAA batts. Those with integrated batteries should be tested in advance of any night riding by simply powering them on for (and recharging after) a day ride or two in order to be sure the lights are functional and battery capacity matches the manufacturer's claims.
Weather matters, too! A few years ago I learned the hard way that cold temperatures have a marked negative effect on battery life. I was riding after work in the winter, which meant nothing but night. It also meant decreasing temps as the season wore on. Somewhere in the 10-20* range, I noticed that my then headlights weren't lasting like they did in the summer. In the end, the cold ended up cutting my rides short due to my inability to rely on the batteries I was using then.
If you plan to ride during actively falling snow, it's worth being aware that a lot of bike lights do not get hot enough to melt accumulating snow from their lenses. If you are aware, it's a simple thing to wipe the lenses free of snow here and there. Otherwise the lights' effectiveness drops rapidly.
In times of more normal temperatures, it's worth being aware of the fact that riding around in the dark, even with lights, can be intimidating at first. Even on a multi-use path segregated from automotive traffic and with good lights, darkness is, well, dark. This is another reason for the helmet light: when you hear something suddenly go scrambling through the bushes just off the trail, it's great to be able to illuminate the spot by turning your head quickly. I almost never spot the source of the sound, but the light helps quickly confirm that it's headed away from rather than toward the trail.
Similarly, when you do spot an animal, especially a herd type animal like a deer, it's well to assume that several more are nearby. I once spotted a deer in my headlights and was enjoying the view as I approached on my bike while it stood motionless. Also motionless and unseen in the dark were the deer's two herd mates. They waited until I was about 3' away before breaking and running into the darkness. Deer are startlingly loud at short range, especially when their presence is utterly unsuspected. The scare didn't last long, but scare me they did. Better to keep the helmet light moving, scanning both the path directly ahead and to either side of it so you know what's there before you arrive nearby.
Riding at night presents the cyclist with new challenges and unique situations, but also unique rewards. I love being out in the deep dusk, for example, seeing the night birds and bats begin to come out as the sun fades away and deepening shadows spread to cover the land. Like snow, darkness can completely change even a well known location or trail into a whole new experience. There's less to see in the dark, but much more to hear. It's worth trying, especially since the lights add a safety factor to day rides by making you more visible to others.
For those who are just starting out, I advise doing your first few night rides starting in full darkness. Dusk is wonderful, but probably the single most challenging visual environment for a cyclist or motorist. Ambient light at even low levels reduces the effect of headlights and creates unusual shadows. I've had a couple of really 'interesting' rides on gravel where the dusk meant I was all but blind to variations in trail quality which were easily visible both during the day and with lights in full darkness.
That's not to say you shouldn't ride during dusk, but be aware that it's actually easier to ride in full darkness then work into the in-between times such as late dusk or early dawn.
Have fun, be safe, and bear in mind that as always, your mileage may vary.
