Doubling Vocals

On several of the projects I'm working on I am doubling lead and harmony vocals. I'm doubling them for two reasons, 1) I love the double tracked vocals The Beatles used, and 2) the usual lack of confidence in my voice that seems rather common among posters here. (Strange, since I was once the lead vocalist in a band. Only vocalist, really, since no one else wanted to even sing harmony. In fact, one of my projects is taking a live recording of this band from the dark ages of 1979 and enhancing the vocals and adding some keyboard parts.)
The problem I run into is that if I have the first track of vocals up at a level that is actually able to be heard by me, I will stray off pitch. If I sing with another voice, I'm fine. It is only when I double my voice, and while using headphones. So far I have had good luck with merely rehearsing to where I sing the parts almost exactly the same every time (ala Freddie Mercury. He was so good at that!), but not hearing my original vocal track while I'm singing always causes uncertainty about the different takes matching, leading to miscues.
I've read a lot about engineers and producers who talk of making headphone mixes for the vocalist that has the voice prominent and centered. That just doesn't work with me.
Does anyone else have this problem, is it just me, or can anyone share their vocal recording techniques?

I have experimented with that some, but haven't been as happy with the results. I'm assuming that I'm not putting enough space between the clone and the original, or modifying it enough to create the result I desire. This is probably due to the fact that I still prefer to do some things as if I were multi-tracking with tape, so I want that same sound that John Lennon used to get from the ADT that George Martin anf Geoff Emerick used. I'll play with cloning and altering some more. Thanks!!
Any other suggestions, anyone?

I think that the slightly off-note singing is what they were going for, unless it's outrageously sharp or flat. Live double-tracking of anything audio will render a nice 'out-of-phase' effect. And you will even hear the Beatles stray sometimes. Greg

I've run into this before.

I know it sounds weird....because it is....... but what I did was to play with the EQ on the original vocal track
to create the infamous "telephone sound" and panned it hard right in the cans.
Then I panned the vocal we were tracking hard left. It worked!...

For some reason the singer was getting lost hearing both of their own vocals coming back at them...so I fed the vocal with the Old Telephone sound back to them for timing and intonation and the brain freeze went away!

Not a usual practice but sometimes a good trick......weird but something to try...

Rob

if all else fails.....throw rocks at it!

I've never tried double-tracking, so I don't know how my intonation will stand up while trying to sing the same thing. I'll have to give it a try. I have cloned a vocal and instrumental track, though. I didn't go into all the little mods Happy Running Dog Face mentioned above.
I lived in Plano (the poor part), Dallas and Terrell. Now I live near Clayton. Greg

Recording in stereo is a product of the digital age, not that it could not be done before, but most tracks were mono and the mix was stereo. What i like to do is get a good solid clean vocal track the clone it twice one i run thru the compressor and the other thru either an echo or a delay effect, and just get it off a fraction of a fraction, one has echo, one is compressed and the original has reverb. theni lower the two clones to a low volume and then raise them until they seem to enhance the main track, i spend conciderable time balancing these tracks out.