For me recently I stack it in siril with 1x drizzle at .9 pixel fraction and force 32 bit. Then stretch it until the nebula is barely visible (depends on object) then use seti astro shapening, then graxpert. Then I remove the stars and stretch the starless image. Then split the color channels and in pixelmath combine the G and B channels, call it O. Then do O minus the R/2-4(depends) and then mess with these in GIMP or pixelmath until I get a result I like, from there mess with the colors in gimp, recombine with the stars and run it through graxpert again if needed