Ok 2 things,
1. You guys saying less is more...don't forget that the original thread was about the big Dre chorus...that is done by stacking at least 2 different takes of the hook on the left and the right. Then (what I personally do is) send them all to a bus and place your compression & eq on the buss. I would then either go for a light verb with a short decay or a little delay effect...but mix it low like has been mentioned....If you need some surgical eq then place that on the actual track..and still eq the bus to taste.
2. Have a listen to the track on my signature...the main vox is one track with one track of add libbs. To get it thick, my little trick is to use a send on the main rap (and the libbs) and send it to a bus. On the bus I have a distortion plug (started doing that co's I wanted a warmer sound to my mic..and ain't got high end gear or money to play with) I then blend some of bussed track back in with the vocal at a low level just so it thickens the bottom end of the vox (works well I think). This is my equivalent to boosting the low end like 'iamthetruth' said.
The hook is then a total of 2 tracks per side done how I said in point 1. It's not perfect and I have improved on that technique by using more tracks (no doubles) on some newer tracks.
"This is what I love about mixing though ...it's never the same twice"!