I have the same issue.
Work on your grip so the club face is straight when it makes contact. Or it could be your shoulders, make sure they stay level.
If those don't work, your knees may be the problem, make sure one doesn't dip on you.
When I played for varsity this year 1 day my drives would all be straight. The next day I had a bad slice.
What I do now is either you aim more to the left and play it like a draw.
Or another one that usually works for me most of the time is set your left foot on the same line as your tee. I always do this but if you dont you should start. If you already do then start practicing puting it ever further up so its past your left foot.
Your club face is open because when you contact the ball your club hasnt had the full rotation. Once it gets the full rotation it is straight and sometimes you need more swing to make it get the full swing.
When I played for varsity this year 1 day my drives would all be straight. The next day I had a bad slice.
What I do now is either you aim more to the left and play it like a draw.
Or another one that usually works for me most of the time is set your left foot on the same line as your tee. I always do this but if you dont you should start. If you already do then start practicing puting it ever further up so its past your left foot.
Your club face is open because when you contact the ball your club hasnt had the full rotation. Once it gets the full rotation it is straight and sometimes you need more swing to make it get the full swing.