WOW I wish my Hungarian Lavender sample made lather like that. I've tried at least 2 different combos and I can't get mine to look anything like that.
I got a new brush that I haven't tied yet (SOC cherry) and I might try it with that sometime soon.
I used Marco's method to lather it which actually resulted in it being to wet. I'd say two shakes of the brush would suffice. Also I put the sample in the bowl and then lathered.