what takes 5 minutes to machine quilt, takes DAYS to pick out. Also, if your quilting tension is bad, rethread the WHOLE machine. Even after you refill the bobbin, it might be the thread wrapped around something RIGHT next to the cone of thread.
make a copy of my pattern to leave with the pieces if I have to stop mid project. When the project is finished, shred the copy. *this saves searching for the 'pink' quilting book for DAYS, when actually its BLUE*
Finally, don't pat yourself on the back until the project is TOTALLY complete. If you crow over how good it looks, you are doomed to having awful tension you have to pick out when you have above mentioned bad tension.