Here's a shot of my 3 prototypes of exhaust plumes;

One on the right is hot glue only, no paint. Second from the right with the khaki pants is central hot glue with some grey paint smeared on and let dry, then coated over with lots more hot glue. Finally on the 2 figures on the left are hot glue formed then painted with white/grey/black. Actual rocketters are in various stages of painting, I'm really, at this point, only considering which type of plume to use.
Post comments about which you prefer and why if any reader is so inclined, thanks.