How To Minimize Phase Issues, Mixing

[lunale]

Hi,

lets say I have double-tracked an acoustic guitar. Alright. Sounds great.
So let's go extreme here: pan one far right and the other one far left.
Ok...huge! Sounds like on guitar from all over the place.
I hit it in mono and it sounds weak. Less loud and somewhat worse. I Know thats because of phase cancellation.
So this goes out to the pros. How can I minimize those phase issues?

And how do you achieve that the both guitars come from outside the speakers, leaving ahole in the middle, and still sound good in mono?

Same with backing vocals. I've heard GreenDay's Warning and there are a lot of tracks where this is done great.

Any Advice?

Edit: Same with delays. Any short delay introduces phase cancelation, right? Can I get rid of it?

Thanks
lunale

[Musiclab]

there shouldn't be phase issues with double track parts what you might be hearing are the flams between the 2. A 50ms delay is also not going to cause a phase issue.
When you hit mono you should hear the image collapse not get weaker