When I render, I’m getting artifacts in the shadows.
How can I either soften shadows from spot lamps, or remove these shadow artifacts?
You seem to be using buffer shadows. To soften them a bit, increase the “Soft” setting under the Shadow settings with your lamp selected - try 5 or 6 to start. You’ll also need to increase the “Samples” value as well - try something like 7 or 8 for that.
If you’re using ray shadows (which is what I typically use), set the “Soft Size” value to 3 or 4 and the “Samples” value to 8 or 10. That usually gives me pretty good results.
When trying to get soft shadows, it’s sometimes useful to use an Area lamp instead - try playing around with that and see what you can get.
Good luck!
Using AO with the lighting tends to soften things up too.