Freeze drying it seems popular lately. I think it can be as simple as putting it exposed in a freezer for a week or 10 days, or as complex as buying a freeze dryer. Should try it with a chunk.
I think the freezer stops it from oxidizing, so it doesn't get darker than it is. Even lighter as the moisture is drawn out.
Long time ago, was in line for clones out on the street of downtown Oakland, was maybe 4 or 5 a.m. Had an older grower tell me how he was getting some godly price for his bubble. He then went on to explain how if the temperature of the water is low enough that it only takes a very gentle agitation to get the resin heads to break off. Also how some of the terps are water soluble.
So get the water extra cold, and a very quick, super gentle agitation, and you will get less contaminates and a better product. Made bubble like this, that would melt in warm weather. Genetics and health of the flower/trim matter as well of course.