One of the first lighting techniques I learned in graduate school was Paramount lighting. It's an easy way to come up with consistently solid portraits of almost anyone. Here's a quick tutorial from Adorama and fashion photographer Lindsey Adler on how to get that just right.
Trying to figure out complicated lighting setups for a portrait is hard, and sometimes there isn't enough time to plan out what you're going to do, so knowing a few lighting setups in the back of your head is important to get up and running. I would list paramount lighting as one of my main go-to setups in photography for this reason. The lighting setup, as Adler says, is based on the style of the old Paramount Pictures movie studio look, with special attention paid to the shadow that falls perfectly under the nose of your subject, though there's an argument to be made that hair, makeup, and wardrobe play as much into it as anything else.
All you really need to accomplish the look is one main light and one background light, and while Adler is using a $4,900 set of Profoto D2 lights, I've easily used speed lights such as the Canon Speedlite 600EX II-RT in the past. Using speed lights is a cost-effective and far more portable solution for my needs.
That said, there's something to be said for having some of the support gear that Adler uses here. As she points out, using a standard light stand can often mean that the stand and light itself are going to be getting in the way of your photography. She uses an Avenger Roller Stand with an Avenger D600 mini-boom to hold her light and get it out of the way. Of course, sandbags are a must to balance everything out and prevent a light from crashing into your model's face.
Adler's preferred lighting modifier is a Profoto Magnum Reflector, which gives a bit more of a harsher look to the light with more contrast. I personally prefer a large Lastolite Ezybox Hot Shoe Softbox Kit for my main light and Fstoppers' own Flash Disc Portable Light Modifier to fit on a speedlight pointed at my background. As Adler points out, the shadow will change as the light and model's head moves, and so while a softbox isn't as precise as Adler's setup, if I'm in the ballpark, this lighting setup can make anyone look reasonably good.
What are some other go-to lighting setups for you? Leave your thoughts in the comments below.