that said...
 
i DO love the beatles, and they were always spot on..
 
and i love Queen, and those vocals are without peer.
 
 
so, i guess i need to practice dotting my I's and crossing my T's
 

 
 
 
back on topic:
 
for my own stuff, i typically sing a lead vox, and then sing it again, doubling it....
and later, i decide whether i need it in the mix or not.
it's easier to do back to back singing sessions when it's fresh in the head.
 
 
then, i will sing two and 3 part harmonies, and double each one of those with another performance.
 
i NEVER copy performances. i do not like the sound of that at all.
 
 
i HAVE experimented with cloned copies, with shifts in time, added flanging, to approximate that old beatles ADT effect...
\
and decided i did not like it, at least not on my voice.
 
i have found that when i sing with myself, i cause phase issues because i sing so close to the original (not saying i sing well, but sing consistent) and the ADT effect seems to compound that problem.
 
i like to pan lead and doubled lead straight up, and hard pan backups depending on the arrangments..
 
i'll pull the backups in to 45% left and right, and all the way in to center.
 
i always add panning automation at the beginning of mix sessions, to all vocal tracks, even the lead.
 
sometimes i use it aggressively, sometimes not at all.
 
it's strictly song dependent.
 

batsbrew
 i NEVER copy performances. i do not like the sound of that at all. i have found that when i sing with myself, i cause phase issues because i sing so close to the original (not saying i sing well, but sing consistent) and the ADT effect seems to compound that problem.

I'm the same way. I won't copy tracks, yet when I double or triple vocals, it tends to cause phase issues. Usually once I settle on a vocal style and melody, I don't deviate at all. So I'll put lead 1 straight up the middle, then put lead 2&3 about 35% left and right, but with the levels down so far that they're just fattening up the main track. Then BG vox I'll double each harmony and place those 80% & 100% left and right. And I absolutely NEVER use V-Vocal on ANYTHING. I despise that thing. I have enough trouble avoiding phase issues on vox without throwing that thing on top of it.

Try using melodyne. I use it and never have phase issues or artifacts. Of course, I'm not generally using it to move notes an octave either.

I used to use melodyne actually.  I'll have to dig it out and see if I can make it work...I don't recall if I was 32 or 64 bit at the time, but I loved the interface.