the riser idea with the white noise works…
Using High-Frequencies:
similar to the white noise filter sweep, you can do the same with cymbal rolls/reversed cymbals, reversed snares/claps, snare rolls clap rolls, or any type of high frequency sound effect, with at filter sweep, maybe some sort of delay. They all create the same effect.
Drums:
Drums fills are great techniques for transitioning from one part of a song to the other, or even to help annunciating a phrase. But yeah: going into a “high-drama” part from a build drop everything for half a measure before that part and put in a drum fill. I think some people may disagree with me but I think it creates good punctuation and even adds more to the building tension/drama in a song.
Musically:
Fade in is probably the simplest way to introduce a new element. This can become long and drawn out and songs just start turning into proggy, shameless acts of self indulgence. When used tastefully it’s effective.
If there’s a recurring melodic theme in your track (which there should be some faint semblance of) try teasing that a bit. maybe not the whole line but bits and pieces here and there. Again, a great device for creating drama, the listener knows it’s coming and that anxiousness builds.
“Tails” work great. Similar idea to a drum-fill, tails are the “ends” of a riff line. Think “Enter Sandman” by Metallica; same thing 3 times then the tail. When used it accomplishes one of two things, when used wisely, BOTH. It lets the listener know that, that particular melodic line is done, AND it leads into the phrase either seamlessly restarting or into another melodic line. What’s good here is that knowing that the phrase is “done” sets up for something else. Now you can move onto different instrumentation, or add a new harmonic element or just a new counter melody, so on and so forth.
last thing That I’ve been playing around with lately, that works great with synths, is the filter cut-off. Now, not just using it to do a sweep or to create wobbles, but in Massive for example you can use and envelope to control the opening of the filter. so you can start with a thin plucky sound and open it up to a huge wide pad. Helps build tension. also I find coupling the same macro to the chorus or other effect really beefs of the sound.
Hopefully these tips help.