I always have lights on my cycles all year round, I don`t like cycling at night anymore but you never know when you may need them. A puncture or any other problem can stop you from reaching your destination before the lights fades. I used battery Cateye lights, the front has 2 modes flash -constant while the rear has 3 modes rapid-flash-constant. They are cheap and the battery life is okay, the front takes 2 AA and the rear takes 2 AAA.
I also have Pedal Reflectors that are cheap to buy and easy to fixed onto your pedals.
Also have a light on my helment, but I`ve only used it once when I got caught out in some thick fog during a morning ride, it wasn`t foggy when I left home.I once set off on a lovely sunny morning and few hours later found myself in darkness in a nasty thunder storm sure needed my lights then.