Only 12 possible positions remain. 1 of them is the solved case. Here is how to solve the 11 others:
If you get one of the other positions, you can just do Allan™, and you will be in a "single Allan™" position.
(An Allan™ can actually be done using
only 2 Sune™, as seen to the right, if you really don't want to learn
many move sequences).
Learn them by heart. And learn to do them fast. You will always need them!
2003 World Champion Dan Knights favors this solution to Bert™. It's a little less straightforward, but can be done in just 4 movements. He explains how with a video here.
I think of the first alternative Arne solution as a 'brute force' one. The second is more of a 'finesse' solution. And the third (Thanks to Doug Li) can be done without shifting your grip. All can probably be done faster by many, despite using more turns, depending on your twisting style.
The other thing you can do is to plan ahead and learn many special top layer cases in the earlier steps, so you can avoid this step much more often than 1 time out of 12.
The advanced cubist will instinctively mix up the cube when this step has been completed, thereby forcing himself to start again at step 1.