This started out as a mix of very underexposed background and slightly overexposed disembodied blue glowing things. After about 45 minutes of editing and a bunch of stacked exposure adjustment layers, plus a load of operator masks, I ended up with this.

And then I turned on a bit of chroma noise reduction, cracked open a root beer and declared it "good enough".

SiEO and Madox (taydathunder)