Make the vocals sound clean: Make sure to use a de esser, and use a gate to remove any breaths or background noise.
EQ: You're going to want to use a low pass filter on the vox to take out any Sub lows. Leave that section for the kick and low instruments. HPF around 80 Hz and boost your voice around 2K Hz.
Not really sure what kind of Hip Hop your working with but I listen to a lot of Odd Future and they use a lot of telephone effects along with pitch shift effects. I'm pretty sure they use logic for their albums.
to get a telephone effect, you should use a pretty heavy amount of compression use the overdrive effect and high pass the vocals around 500 hz and also low pass the vocals. Boost at 2 K again.
Pitch shift is pretty self explanatory.