Insert editing/crossfade tips?



* Here's what I need to do:

Using multiple takes of a single song performance from a field recording session (of pipe organ music, as it happens), create a final demo recording of that song that's as (artificially) perfect as it can be. As in, "oh, the performer really screwed up that riff in take 4 but the rest of the take was brilliant -- let's replace those 3 seconds with the same riff from take 13 where he nailed it." The portion of the wave file containing the bad riff is overwritten with the pasted-in copy of the good riff from another take. That sort of thing.

* Here's what editing software I have:

CoolEdit 2000, Sound Forge XP and an old copy of Red Roaster that I could scare up and reinstall.

* Here's what I need help with:

I'm not sure which techniques I need to learn about to get this done...clearly insert editing comes to mind, and quite possibly crossfades. The essential problem, of course, is that "punching in" with material from another take needs to be imperceptible, so I've played around with using a Mix Pasting operation (in Cool Edit 2000) with a bit of crossfade, with mixed results (heh). Sometimes it seems to work, other times the transitions are quite audible.

Am I on the right track here? What's the general approach to doing this kind of edit? i.e. I find a place in the music where notes are being held or otherwise not changing momentarily, get my wave file cued up as to exactly where and how long I want to overwise insert the external clip, then I mark my insertion clip and copy it to the system clipboard...but THEN WHAT? What's the best way to trick the listener into thinking that the performer played the piece perfectly in just one take?