there are some plugins that help with that, but if you can, always record two separate tracks.
If you only got one track you could try the following:
If you still have more than one take for comping, make two different tracks from it, even if one is not played perfectly.
If you have more than one chorus or verse, swap e.g. the tracks from the choruses to get two different tracks.
Or even, if you have some same chords within one chorus, copy single bars to other places to get two different tracks.
If you can't any of that and you have to use the same track, make the copy also different in other ways than just with delay. Change it with EQ a lot, use saturation on both but on different frequencies…