Looking to Break Past 350ft. Barrier

[crunchystix]

Been playing for a little over a year and a half. Constantly working on form but as of now my very best drives in field practice are only getting to about 350ft.

I think my arms are pretty decent form wise, and the biggest things I've been focusing on lately have been tucking the back arm and getting my front heel down.

I know my rear leg isn't doing what it's supposed to and there's definitely a ton of room for improvement overall. Any help would be greatly appreciated, and I know there are hundreds of drills out there, just curious of any that could be most important for me.

Thanks so much for any help! Here's a link to my most recent form video:
https://www.youtube.com/watch?v=NCfff_A5Zyc

[sidewinder22]

You are just kind of stepping backward into the plant, instead of making a lateral shift into the plant.
https://www.youtube.com/watch?v=GxnhM5amro0#t=1m34s
https://www.youtube.com/watch?v=Nu4CzVnITlo#t=5m56s