Bunker play is a bit like chipping, at least when it comes to your address position. As you did for the chip shot, you want to create ‘impact’ at address.
So set up this time with your sternum directly above a point about an inch behind the ball. In other words, above the area of sand you want the sole of the club to enter the sand as you skim it through.
Again, you want most of your weight – about 90% – on your left side. Again, you want to leave it there throughout the swing. That has the benefit of angling your shoulders downward from right to left, which allows you to make a slightly steeper than normal backswing and forward swing and encourages you to ‘skim’ the club through the sand. When you get that right, the ball flies out high and soft. Perfect.
How open?
Good bunker technique revolves around a good set-up position. For me, that involves letting the length of the shot

I am playing dictate how far left I aim my body at address and how much I open the clubface. It’s a trade-off.
The simple rule of thumb that I follow is that for every degree I open the clubface, I open up my body by the same amount. So, for a standard greenside shot, a line along my feet will be aimed roughly 30 degrees left of the flag, the clubface opened until the leading edge is aligned 30 degrees right of the flag – as we have illustrated here (left). If I want the ball to go further than normal, I square up both my stance and the clubface.
If I don’t want the ball to go as far – say, when I want a very soft pop-up type shot – I would significantly open both my stance and the clubface until I was satisfied that I had the perfect set-up for the shot (right).
One last thing. Even the briefest of glances at all the best sand players reveals that every one of them has a significant bend in their knees at address. They ‘sit down’ to hit bunker shots. You should, too.