Really like how you did that green OSL. I could use that for my necrons. Man, those models just look amazing, very well done sir.
How did you do that and what colors did you use?
Ok, for OSL techniques, there are a ton of tutorials and write ups online, including one I wrote myself.
Basically, you paint the mini normally, then add the lighting at the end. When painting minis that have normal lighting as well, it is important to make lit areas lighter than other areas on the minis, and the source itself needs to be the lightest part of the mini (in this case it is the bottom of the flames and fingers area).
For placement, mostly you turn the mini sideways and highlight up that way. Assume that light travels in straight lines, and light areas by imagining straight lines drawn from the source. Then it is a matter of making the places closer to the source lighter than other places.
The colors I used for the green are a mix of P3 Gnarls Green, P3 Necrotite green and pure white. The source went all the way up to pure white.