re recording vocals tomorrow. good techniques?

If you comp on the way in, you can't un-comp.

If you track raw, then comp.....you can always go back and un-do FX.

If you have experience and know what you're doing, I imagine comp'ing on the way in could yield good results as long as its not overdoing it.

Main advantage I feel is to prevent clipping. I hate riding gain by hand. I'm compressing no more than 5dB on the loudest parts on the way in.