Four + years in and this still isn't a key feature of my bowling and still remains to be one of the key components that needs to be added. The Big Leg Break requires (in my opinion) either a wholly natural and therefore unconcious perfect wrist presentation with the big flick off the fingers. Or, very good awareness and control over your motor skills in order that when you bowl you are aware of the wrist presentation and can flick the ball from the fingers with perfect timing in conjunction with the flick of the wrist at the right point through the arc of the arm as you bowl.
Because of my knackered leg, I've been flicking the ball in the manner that is required watching the seam presentation over short distances making sure that it is rotating perectly 90 degrees to it's direction going forwards. The more I do it the more for me purposely I have to bowl with the feeling that I am almost bowling with the wrist turned so far round clockwise it feels as though I'm bowling with a Karate Chop action. On my youtube channel I've had several people ask me for advice primarily relating to the Googly Syndrome where they've lost the ability to get the ball to break towards Off and their Leg Breaks either do not turn or turn towards Leg (Googly). The easiest remedy for this is to not bowl the Googly anymore and work with this feeling that you're turning your wrist so far round that it feels like you're bowling with a Karate Chop action. Possibly as a hang-over from my Googly Syndrome days this is the modus operandi that I still have to follow in order to get the ball to turn big. In order to do this I find that I really have to focus and concentrate exceptionally hard on my fingers in order to flick the ball from the hand and have the wrist in what feels like a karate chop position. When I do it, it comes out very well and this was the case a few days ago and since then I've been bowling non-stop with this kind of action.
The thing that still surprises me with the Leg Break is the complexity of it and the difficulties that some people like myself have with bowling it and the ease that others bowl it with. Having said that the majority of people that do bowl the leg-break have only a rudimentary grasp of its potential because they basically stick with the stock ball and a limited number of variations, keeping the whole thing really simple and allowing themsleves to develop their stock ball to a good level. Having said that though I've only ever seen 2 or 3 good Leg break bowlers and attempts at discussing the finer issues of their actions with them have drawn a blank because they have become Leg Break bowlers it seems through natural ability.