Adding characters + lighting to a scene

So I was commissioned to do this piece consisting of a sort of blend of sci-fi and medieval city in the background with a foreground with three different characters around a bonfire. Now, I find this to be a bit of a tricky thing to get my head around even after years of painting, but I want to share my general process of how I go about it. NB: In this example, I'm already assuming you have a base image to work off of.

Identifying light sourceThis is not a slavishly systematical approach in any way - in retrospect it would probably be more helpful to sketch out your characters placements, but this also works. We know we want a bonfire, which will be the main light source in the foreground. Draw some sticks, and paint fire on top. ez. There it is, the main light source, which currently isn't emitting a lot of light. Let's add that next.

Light emission For lighting up the surrounding surfaces, you can use either colour dodge or linear dodge on a seperate layer, with a darker, saturated colour from the fire, like a dark orange. The further away from the light source, the less the light will travel; therefore I'm using a very soft brush to create a steady gradient around the bonfire.

Merge down and paint overThis is a step that's a bit difficult to explain outright without going into heaps of detail. I often find it useful to merge layers as I paint - especially with a lighting scenario like this. I've just experimented on this but using some more painterly brushes to indicate soil and grass. Also I've lit up the area using the dodge tool in photoshop. (If your program doesn't have dodge tool, using colour dodge with a gray hue is functionally the equivalent)

Add rocksRocks are like little characters. They're also easier to draw than characters cus they can be whatever shape you want, so they make perfect practice for testing of the lighting scenario. Draw rock shape -> imagine the light from the bonfire hitting the rock -> paint the light side -> add ambient light to the shadow-y side of the rock. :) A bit oversimplified, but hopefully it's somewhat helpful. They're easier objects to work with and figure out how to add lighting and shadow to around this bonfire.

Add character shapesI definitely should've planned this better, but coincidentally, the rock to the bottom left coincides perfectly with the placement the commissioner wanted for one of the characters! So I'll have this ambigious blob just sitting/leaning against it. This part is simply figuring out placement, basic pose, and scaling.

Rendering the characters This is definitely the part of the painting process that is most time consuming, simply because of perspective and anatomy. However, these aren't very humanoid characters so in my experience you can get away with a lot more without it looking off. But the focus here is (most importantly) the lighting. My process for characters is usually: refine shape -> refine anatomy -> add local colours -> multiply for shadow -> colour dodge/linear dodge/overlay for highlights -> merge down and paint over. And whoop, 2 hours later you might get this :)

Again, this is not a strict guide to follow - just one of many processes to get to a desired result. You could render this out way more of course, but this works for what it is. Hopefully any of this was helpful. Let me know if it was, and thank you for being a patreon supporter <3