transitioning from one bar to the other u can do all sorts of shit, drum rolls, reverse snare, atmosphere sounds like planes flying, machine guns, anything that sounds like its building up for something, using stuff like thunder or expolisions for when the drop comes in gives it more of an impact, gunshots, its all about positioning and timing
obviously not just effects, structure your drums so the tuning on em gives a sound that builds up, change the velocity on em so they get louder and louder as it's about to change into the nex bar, like somethign is coming, or something is falling.. something is gonna hit hard...
flip the instruments in different ways near the end of the bar, add extra instruments...
stuttering that shit before the end of the bar (...........) (...........) (............) (. . . .) POW
get creative on that shit