Step 4: Heat and Shape
Working with the vinyl is a funny thing. When it gets hot the vinyl is floppy and feels almost like fruit leather. After a few seconds you can shape the vinyl and it will begin to hold its shape. At this point, start working the material as fast as you can. Even with just 12 bends to make on the record I didn't have enough time to get everything right.
The good news is that you can hit the reset button by putting the record back in the oven. If you want to completely start over, heat it until it gets back to the floppy stage.
To just finesse a couple parts of the piece you will have to be much more attentive. Turn the light on in the oven if you can and watch carefully. Once the record starts to sag just slightly, open it up and take it out. This should give you enough time to fix a couple of bends. Repeat as necessary.
If you have a heat gun you can heat up a localized area to make specific fixes.