Before trying to replicate the skills and drills featured in these video clips, it is important that your talk to your coach to work out what is best for you and then practice, practice, and practice some more.
These notes, prepared by Hobart Aquatic Centre Masters Swimming Club Coach Philip Tyrell, cover the important points of developing a great backstroke.
The video clip, The Secret to Perfect Backstroke Technique, takes you through all the phases of swimming backstroke well. Note the emphasis on rotation.There is lots of slow motion vision with great instructional commentary matching the vision. View this clip.
Talk to your coach to work out what is best for you and then practice, practice, and practice some more.
In this clip, Backstroke Swimming Drills | Single Arm, you will see a demonstration of an arm rotation drill. A good alternative is to do three arm stokes, rotating each time before doing the required number of kicks. If you have developed the requisite leg strength you can start doing this drill without flippers. View this clip.