Yeah, use an HP filter to begin removing the lower frequencies as your song approaches the drop (make sure that the HP filter your using doesn't have a lot of resonance (Q-value) as it's sweeping away the lower frequencies (20Hz-250Hz/300Hz)). Reverb is also a crucial effect for conveying the spatial aspects of the sounds in your mix. That being said, you can start to apply conservative amounts of reverb to your mix as you approach the drop (automate it so that the 'wet' value is steadily increasing throughout the build). This give the listener the impression that your sounds are getting further and further away. Also, if you're willing to include another synth in the build, you can program a synth to oscillate its pitch up and down. I've heard many sounds with very stunning drops take advantage of the fact that the human brain starts to become nervous when hearing such a sound. If you can get people to hang on the edge of their seats, do it! If you can't work in another synth you could try using a phaser. Again program it to start shifting the frequencies upwards during the final couple seconds of the build (an effect similar to this can be achieved with a delay plugin by automating the "time-value" of the delay to decrease. The time in between delays becomes shorter, the freq. goes up and so the perceived pitch generated by the delay will rise. I've given you some specific tips to work with, now I'll give you a more general concept that seems to be important when creating a build-drop event. The impact of your drop will depend, in part, on the contrast your able to produce between the final moments of the build and the initial moments of the drop. The HPF creates a bass vacuum to condition the listener for the bass that's about to be produced by the drop.
You go from (Bass Vacuum- Practically no low frequencies)----> (Lot's of lower/bass freq.)
(Lot's of reverb/smeared sounds)------>(No reverb, in-your-face sounds)
The contrast is crucial for drops to be executed properly. But don't forget about your builds either. I hope at least some of this was helpful.
