Players can miss-strike shots because they lift and drop their spine angle through the swing.
This lifting and dropping causes an inconsistent approach angle into the ball.
A good drill to help this poor movement is to ask a friend to hold a golf club so that the handle is on the top of your head.
Hit some practise shots and each time try to keep your head touching the club with the same amount of pressure as when you started.
When you are hitting the shots, once you strike the ball ask you friend to move the golf club out of the way quickly so that you are able to keep moving easily into your through swing.
If you drop the spine slightly in the downswing that is fine.
Once you are both happy that you are not raising or dropping your spine angle too much through the swing, hit some normal shots using the same feeling you have gained from the drill.
Practicing this will help you strike your woods and iron shots better and more consistently.