A few tips, they will fade after a season in the sun, so if youre doing them now, I'd suggest 3 coats of night shade. Don't be worried if they look REALLY dark, they still let a good amount of light threw. I dont suggest doing the headlights however, when the lights are on, it makes the lights look purple, spotty, and uneven (JMO)
I took a palm sander to mine with 150grit paper, then 1000grit by hand, then 200 by hand. Wash, dry, paint. Do light coats or it can get the orange peel effect. I did a light coat every 20 minutes, and after the 2nd clear coat, did two heavier coats. Don't handle the lights for a few hours after your last coat...you don't want to spend all that time working on them just to get a finger print on them when theyre still sticky.
I also didnt wax or wetsand them after the clear coats, just put them back on. Still look flawless after a car wash over a year later.