I generally use compression and highpass at like 100 depending on the vocalist range and proximity effect of the mic. some mics will have too much fucking bass (sm58). Also, I tend to work around the 1k range to reduce some of those "telephone" mids. Be careful about them low mids as well, they can cause them muds. It's all very dependent on the vocalist, style, and the mix. If the vocals are the focal point of the songs, they gotta POP!
I also like to have a fun track where I send the vocal and just destroy the fuck out of it. Distortion, fuzz, phaserz, bit crushing the fuck out of it. whatever and blend it in. Can add some nice character, but you always have to be careful not to muddy things up or make it too distracting. I'm currently working on a project where I really like smashing the main vocal track with a little distortion, and then underneath I've got a 4-bit version that sounds like the speech from the Sega Genesis game Altered Beast:
WELCOME TO UR DOOM!