It may sound totally illogical to say this but the backswing WILL FIND YOU once you know where impact works from and how to finish the swing. Whilst there are options it truly is just a place to build space and room from. It doesn't have to be perfect as history proves....
Key #1 to creating a nice backswing that can help all golfers be better in the downswing and approach to the ball is getting the left heel up. Here is how it is actually done- rather than just trying to do it on it's own accord.
What is the best angle for the right leg to create on the backswing? There are options but here is my take on which option can serve you best- especially if your transition and downswing causes you trouble.
Learning to release the club from the 430 entry path opens up a host more backswing options to assist you to hit the ball correctly. There is only a perfect backswing for YOU- not a perfect backswing for ALL..... 
Cupped wrist or Bowed wrist? As a carryover from a previous post relating to Jack Nicklaus and his thoughts- here's the video to help distinguish the difference and what is easier to perform for a better game