As a lower rank, it’s very useful to learn good basic escapes from every bad position, because to put it mildly you get plenty of chances to “practice” being in a bad position, a whole lot more than you probably do as you get better at jiu jitsu.
Below are a bunch of videos with brief comments on different variations of escaping back control. At first glance, you wouldn’t think there are many options here. But it seems that people prefer different ways to escape, and the only rule of thumb is there is no rule of thumb.
A very effective escape involves bringing the choking arm (top one) over the head. Once you do, you can either drive into the arm as Robson Moura does in the first video below, or scoot away from the arm and get your back to the ground.
Scoot down and reach hand back around your opponents neck:
A similar idea is followed up in no-gi with a Brabo choke:
You can instead slide away from the arm over their leg as the second technique in the following video shows.
Another take on the same technique:
Here’s a no-gi escape away from the choking arm against seatbelt control:
And the same escape but with the gi (and in Portuguese):
And now the same but if the opponent has both lapels:
The same principles as shown in the first video applied to a triangle-body-lock style back control: