shot from the hip

offhand spontaneous unscripted

ad-lib fake

dashed off extemporaneous extempore extemporized faked improv improviso off the cuff played by ear spur-of-the-moment thrown off tossed off unpremeditated unprepared unstudied vamped whipped up winged

deliberate planned

ad-lib extemporaneous improv improvised improviso offhand played by ear spontaneous spur-of-the-moment unpremeditated unprepared unrehearsed unscripted whipped up winged