Over the past year, I've been disciplining myself on frogging a project at the point when I realize it's going south. This has been extremely difficult in some cases, but well worth the added hassle when I finally finish.
Two projects right now are at the frogging stage. #1 is the red sweater set: I realized the shoulder decreases were not going to meet up properly, so I've frogged all the panels back to the pre-decrease point. *sigh* The other project is my quilted headboard. I didn't properly baste/pin down the quilted lining and now, even though the lining will be concealed, I'm ripping out stitches to fix it.
The main problem with do-overs is the momentum isn't there. So I've imposed a "no new projects" rule until I finish these two. Yeah, we'll see how that goes!