Set-up drills are easy and require zero extra effort.
Splaying your left foot more than you normally would do – I would possibly exaggerate that to around 30 degrees – does two things, and both will help your game.
Build up torque
On the backswing, it’s going to give you a bit more consistency and hip resistance, which will give you less lower half movement.
That means that the torque that you build up in the backswing as your top half rotates against your bottom half will stretch right across your core.
Splaying out your left foot builds elasticity in your swing and power, but it also allows your left side to clear on the downswing.
And because your top half and bottom half are a bit more separated than normal, you get a much more powerful movement.
How it works
What you’ll feel is a greater strain when you’re turning back, which is the feeling you should try to get when you set-up normally.
It will feel like you’re winding up, because your left hip will not move as much as it normally would. That’s not a bad feeling to have.
Even if you feel as though you can’t quite get to a full backswing position, the fact is because the torque is there it’s still going to be more powerful than if the left foot was square on.