I have a higher index than you, so take this with a grain of salt. However, I have struggled through this issue numerous times. I have taken lessons and done a ton of research on it because I was so frustrated. I even recorded my swing and saw what I was doing. So, this is what I have learned.
There are ton of reasons why people shank the ball, but they tend to come down to a couple of things. Swing path or lunging a bit. I would estimate 90% of people do it from swing path. You can shank it by coming outside-in or inside-out, but most people do it from an outside-in path. For me, it tends to come from hacking down on the shot and it just gets worse as I get frustrated.
The quickest way I have found to fix it is to put a tee (or a 2x4) a couple inches outside the ball and hit the ball without hitting the tee or the board. Basically, promoting an inside-square-inside swing. This has helped most people I have talked to.
The lunging thing is another possibility, but it is a little less common. For that, a lot of the previous suggestions are great. Setting the ball up on the toe usually fixes it. However, ultimately, you would want to maintain your spine angle and quit lunging.
Again, I don't claim to be an expert. This just happens to be something I have experienced and spent a lot of time researching. I haven't hit one in quite a while, but I feel like an addict that will never fully be cured :) I hope you figure it out because I know how frustrating it can be.